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fHE  J5TORY  OF  THE  I\OCKg. 


POPULAR  GEOLOGY. 


J.    DORMAN    STEELE,    Ph.D. 

FBLLOW  OF  THE  GEOLOGICAL  SOtlETY,  LONDON,   AND  AUTHOR  Of 
FOURTEEN-WEEK9  SERIES  IN  PHYSIOLOGY,  PHILOSOPHY, 
CHEMISTRY,   AND  ASTRONOMY. 


]£y  heart  is  awed  within  me,   when  I  think 
Of  the  great  miracle  which  still  goes  on 
In  silence  round  me  —  the  perpetual  worle 
Of  Thy  creation,   finished,  yet  renewed 
Forever. ''  — BRYANT 


A.    S.    BARNES    &    COMPANY, 

NEW    YORK    AND    CHICAGO. 


1875. 

LIBRARY 

UNIVERSITY  OF  CALIFORNIA 
DAVIS 


TIJE  FOURTEEN  WEEKS'  COURSES 

IN 

NATURAL    SCIENCE, 

BY 

J.  DORMAN    STEELE,  A.M.,  PH.D. 

Fourteei]  Weeks  iij  Natural  Philosophy,  .     .  $1.50 

Fourteeij  Weeks  iij  Cljenjistry,      .    .    .     .  1.50 

Fourteeq  Weeks  iij  Descriptive  J^stroijomy,  .  i  50 

Fourteeij  Weeks  irj  Popular  Geology,      .     .  1.50 

Fourteeij  Weeks  iq  Hunjan  Physiology,  .    ..  1.50 
A  Key,  containing  Answers  to  the  Questions 

and  Problems  in  Steele's  14  Weeks' Courses,  1.50 

4   HISTORICAL  SERIES, 

on  the  plan  of  Steele's  14  Weeks  in  the  Sciences, 
inaugurated  by 

\  Brief  History  of  tlje  Urjited  States,     .    .    1.50 

The  publishers  of  this  volume  will  send  either  of  the  above  by 
mail,  post-paid,  on  receipt  of  the  price. 

The  same  publishers  also  offer  the  following  standard  scientific 
works,  being  more  extended  or  difficult  treatises  than  those  of 
Prof.  Steele,  though  still  of  Academic  grade. 

Peck's  Gaijot's  Natural  Philosophy,   .     .    .  1.75 

Porter's  Principles  of  Cfyerqistry, ....  2.00 

Jarvis'  Physiology  aqd  Laws  of  tyealtlj,      .  1.65 

Wood's  Botanist  aqd  Florist,   .    .    .    .     .  2.50 

djanjbers'  Elenjeijts  cf  Zoology,   ....  1.50 

'tyclijtyre's  ^stroijomy  aqd  the  Globes,    .     .  1.50 

Page's  Elenjeqts  of  Geology,    '.     .     .    ,    .  1.25 

Address  A.  S.  BARNES  &  CO., 

.  Educational  Publishers, 

NEW  YORK  OR  CHICAGO. 


ENTERED  according  to  Act  of  Congress,  in  the  year  1870,  by 

A.    S.    BARNES    &    CO., 
In  the  Office  of  the  Librarian  of  Congress,  at  Washington. 


TO 

MY   PUPILS, 


WHOSE 

NEEDS  FIEST  SUGGESTED  THE  PLAN  OF  THIS  SERIES, 

AND 

IN  WHOSE  APPRECIATION  AND  LOVE 

1  HAVE  FOUND  MY  CONSTANT 

SATISFACTION      AND      REWARD, 


is 
AFFECTIONATELY  INSCRIBED. 


a^nfr 


C  E. 


present  work  is  based  upon  the  same  general  plan 
as  the  preceding  ones  of  the  series.  The  aim  is  to 
make  science  interesting  by  omitting  the  minutiae  which  are 
of  value  only  to  the  scientific  man,  and  by  presenting  alone 
those  points  of  general  importance  with  which  every  well- 
informed  person  wishes  to  become  acquainted.  The  thing 
is  of  more  value  than  the  name.  A  pleasant  fact  will  be 
recollected  long  after  an  unpronounceable  term  has  been 
forgotten.  Therefore,  only  enough  geologic  nomenclature 
is  used  to  make  the  study  systematic,  to  awaken  a  love  for 
the  order  of  nature,  and  to  afford  a  plan  around  which  other 
knowledge  may  crystallize. 

The  author  is  satisfied  from  his  experience  as  a  teacher 
that  pupils  take  no  interest  in  the  fossils'which  characterize 
the  various  geologic  epochs,  except  the  few  which  are  typi- 
cal, unless  they  have  access  to  a  paleontological  cabinet ; 
in  that  case,  they  learn  the  names  best  by  association  with 
the  objects.  If  any  attempt  is  made  to  name  and  illustrate 
the  fossils  of  any  group,  the  limits  of  a  small  text-book  per- 
mit but  a  scanty  selection,  which  is  of  little  value  in  the 


6  PREFACE. 

identification  of  the  fossils  gathered  by  a  class  even  within 
the  limits  of  that  group,  while  to  those  outside  it  is  useless. 
Hence  a  school  Geology  should  give  only  the  general  out- 
lines, leaving  to  the  teacher,  with  a  copy  of  the  survey  of 
his  own  State,  and  such  collections  as  he  may  have  or  can 
gather,  to  impart  the  instruction  in  local  paleontology.  The 
author  has  sought  to  develop  the  following  peculiarities : 
(i)  To  give  the  general  outlines  of  each  subject,  and  only 
enough  of  the  details  to  interest  without  burdening  the 
mind ;  (2)  to  develop  the  theories  of  the  science  thor- 
oughly, and  thus  afford  a  clear  idea  of  the  methods  of  geo- 
logic study  as  a  basis  for  future  progress ;  (3)  to  give 
blackboard  analyses  of  each  subject  for  topical  recitations ; 

(4)  by  means  of  foot-notes  to  present  the  pupil  with  much 
geologic  literature,  thus  affording  the  information   and  cul- 
ture of  an  extended  range  of  collateral  scientific  reading 
which  would  otherwise  be  within   the  reach  of  few  pupils  ; 

(5)  to  add  the  benefits  of  the  "question  and  answer"  sys- 
tem to  those  of  the  topical  method  by  means  of  a  set  of 
thorough  review  questions  at  the  close  of  the  book ;  (6)  to 
lead  the  pupil  to  a  study  of  natural  objects  by  treating  very 
fully  the  stones  common  in  the  Drift,  and  thus  giving  prac- 
tical field-work  at  once ;  (7)  to  adapt  the  book  to  all  sec- 
tions of  our  country  by  means  of  a  clear  presentation  of  the 
typical   New  York  system,  and  such  modifications  in  the 
text  or  foot-notes  as  will  enable  any  pupil  to  make  the  ap-. 
plication  to  his  own  State. 

It  is  -hoped  that  this  book  will  render  the  study  of  Geol- 
ogy possible  to  young  persons  striving  after  self-education— 
to  men  of  business,  whose  leisure  allows  only  a  -limited  ac- 
quaintance with  books,  and  to  schools  where  the  fresh  buoy- 
ant spirits  of  youth  are  now  repelled  by  cold,  formal  state- 
ments of  purely  technical  truth.  The  author's  most  earnest 


PREFACE.  7 

desire  is  to  awaken  the  thought  and  quicken  the  imagina- 
tion of  the  pupil ;  to  lead  him  to  trace  in  nature  the  hallow- 
ing and  refining  influence  of  Divine  truth,  and  thus  to 

become  one  of  that  happy  number  who 

£n*u*vi/v 

"  As  by'  some  secret  gift  of  soul  or  eye, 
In  every  spot  beneath  the  smiling  sun 

See  where  the  springs  of  living  water  lie." 

The  author  would  take  this  opportunity  of  thanking  the 
following  teachers  and  friends,  who  have  aided  him  through- 
out this  entire  series  with  many  valuable  suggestions,  as 
well  as  in  the  reading  of  manuscripts  and  proof-sheets  : 
L.  S.  BURBANK,  A.  M.,  Teacher  of  Nat,  Science,  High 
School,  Lowell,  Mass.  ;.J.  J.  STEVENSON,  Ph.  D.,  Prof,  of 
Geology,  West  Virginia  University ;  S.  G.  WILLIAMS,  Ph.  D., 
Prin.  High  School,  Cleveland,  Ohio  ;  J.  W.  P.  JENKS,  A.  M., 
Prin.  Middleboro'  Acad.,  Middleboro',  Mass. ;  A.  D.  SMALL, 
A.  M.,  Prin.  High  School,  Rockland,  Maine ;  A.  P.  STONE, 
A.  M.,  Prin.  High  School,  Portland,  Maine ;  B.  S.  POTTER, 
A.  M.,  Prof,  of  Nat.  Science,  Illinois  Wesleyan  University ; 
C.  H.  CHANDLER,  A.  M.,  Prin.  Norwood  Ladies'  Institute, 
Northampton,  Mass.,  and  many  others  who  have  kindly 
furnished  the  rich  fruits  of  their  experience. 

The  author  takes  great  pleasure,  also,  in  acknowledging 
his  particular  obligations  to  Foster's  Mississippi  Valley, 
WinchelFs  Sketches  of  Creation,  and  Agassiz's  Geological 
Sketches,  Many  of  the  drawings  are  copied  from  nature  ; 
the  ideal  views  are  taken  from  Figuier's  World  before 
the  Deluge.  The  Scenic  Descriptions,  which  are  a  pe- 
culiar feature  of  the  book,  are  rhetorical  flowers  culled 
from  the  broad  field  of  geologic  literature.  The  Glos- 
sary at  the  close  of  the  work  is  based  upon  standard 
authorities. 


8 


REFA  CE. 


The  author  would  recognize  his  obligations,  in  general,  to 
the  following  authorities  : 

Manual  of  Geology       .        .        .        .        .  DANA.  . 

Manual  of  Mineralogy DANA. 

.  Geological  Sketches AGASSIZ. 

Methods  of  Study         .        .        .        .        .  AGASSIZ. 

Travels  in  Brazil AGASSIZ. 

Elements  of  Geology    .        .        .        .        .  HITCHCOCK. 
The  Mississippi  Valley        .        .        .        .    .  FOSTER. 

Our  Planet .  DENTON. 

Chips  and  Chapters      .        ...        .  PAGE. 

Elements  of  Geology PAGE. 

The  Earth's  Crust PAGE. 

Past  and  Present  Life  .         .        .        .        .  PAGE. 

Medals  of  Creation        .        .        .        .-.;-..  MANTELL. 

Wonders  of  Geology MANTELL. 

The  World  Before  the  Deluge     .        .        .  FIGUIER. 

Elements  of  Geology    .        .        .        .        .  LYELL. 

Earth  and  Man      .         .         .         .         .         .  GUYOT. 

Vegetation     des     Diverses     Periodes    du 

Monde   Primitif        .  .        .        .  F.  UNGER. 

Recent  and  Fossil  Shells      ....  WOODWARD. 

Man  in  Genesis  and  in  Geology  .        .        .  THOMPSON. 

Acadian  Geology .        .        ...        .        .  DAWSON. 

Old  Red  Sandstone HUGH  MILLER. 

Testimony  of  the  Rocks        .        .        .        .  HUGH  MILLER. 

Popular  Geology HUGH  MILLER. 

State  Report  of  New  York    ....  HALL. 

State  Report  of  New  Jersey ....  COOK. 

State  Report  of  California    ....  WHITNEY. 

State  Report  of  Illinois         .        .        .        .  WORTHEN. 

State  Report  of  Pennsylvania       .        .        .  ROGERS. 

Manual  of  Geology EMMONS. 

Elements  of  Geology ANSTED. 

Siluria  (fourth  ed.,  1867)       ....  MURCHISON. 

Sketches  of  Creation    .        .       .       .        .  WINCHELL. 


SUGGESTIONS    TO    TEACHERS. 


*T^HE  author  has  followed,  in  general,  the  classification 
•*•  given  in  Dana's  Manual  of  Geology.  The  teacher  will 
therefore  find  that  book  of  great  value  for  reference.  In 
the  eastern  States,  tfctchcock's  works  are  of  especial  ser- 
vice. The  geological  report  of  one's  own  State  is  essential 
to  furnish  local  information^  and  to  enable  the  teacher  and 
pupil  to  identify  the  fossils  they  may  gather.  Geology  can 
be  pursued  without  a  cabinet,  and  yet  a  small  collection  of 
the  most  common  minerals  is  almost  indispensable,  and  can 
easily  be  obtained  for  comparison.  Fossils  are  more  diffi- 
cult to  secure.  The  teacher  must  rely  mainly  on  his  own 
collection  and  exchanges  with  friends.  Plaster  casts  of 
typical  genera  and  species  can  be  purchased  of  Prof.  Henry 
A.  Ward,  of  Rochester,  N.  Y.  They  answer  all  the  purposes 
of  instruction,  and  in  color  and  form  can  scarcely  be  dis- 
tinguished from  the  original  specimens.  Information  con- 
cerning the  cost  of  small  cabinets  can  be  obtained  of  the 
publishers  of  this  work.  Geological  excursions  to  river 
channels,  quarries,  ravines,  railroad  cuttings,  mines,  gravel 
beds,  stone  fences,  &c.,  furnish  most  valuable  information 
and  healthful  recreation.  A  steel  hammer  of  the  form 


10  SUGGESTIONS     TO     TEACHERS. 

shown  in  Fig.  i  will  be  found  most  generally  useful  ;  the 
edges  should  be  square,  the  socket 
FlG-  *:  large,  the  handle  strong,  and  the 

entire  weight  about  two  pounds. 
Rock   specimens   should   not  be 
12  over  three  inches  square  and  an 

A   GEOLOGICAL   HAMMER.  ,         ,    .     .  ,        -  111  i 

inch  thick,  and  should  be  neatly 

trimmed.     The  locality  of  each  specimen  should  be  care- 
fully noted  and  preserved. 

The  diagram  -at  the  commencement  of  each  general  sub- 
ject forms  an  analysis  of  the  topic.  The  author  is  accus- 
tomed to  have  this  placed  upon  the  blackboard,  and  to 
conduct  the  recitation  from  it,  without  asking  questions, 
excepting  as  occasion  may  suggest  the  necessity  of  addi- 
tional information,  or  a  closer  investigation  of  the  pupil's 
knowledge.  Questions  for  review  are  given  in  the  Appen- 
dix. It  is  suggested  that  teachers  instruct  their  pupils  to 
assign  such  fossils  as  they  may  find,  or  have  the  privilege  of 
examining,  first,  to  the  sub-kingdom ;  second,  to  the  class ; 
and  third)  to  the  order,  but  not  to  the  family,  genus,  or 
species,  except  in  case  of  well-known  fossils.  Better  satis- 
faction will  be  given,  and  results  secured,  by  doing  so 
much  well,  than  by  a  vain  attempt  to  teach  everything  in  a 
brief  school-term. 

Never  let  a  pupil  recite  a  lesson,  nor  answer  a  question, 
except  it  be  a  mere  definition,  in  the  language  of  the  book. 
The  text  is  designed  to  interest  and  instruct  the  pupil ;  the 
recitation  should  afford  him  an  opportunity  of  expressing 
what  he  has  learned,  in  his  own  style  and  words. 


-CONTENTS. 


I.  PAGE 

INTRODUCTION,.        .        .        .      ..       •        •        -17 

II. 
LITHOLOGICAL  GEOLOGY,       .        .       .       .35 

III. 
HISTORICAL  GEOLOGY, 91 

IV. 
THE  AGE   OF  MAN, 241 


APPENDIX. 

QUESTIONS,     . 257 

GLOSSARY, 275 


INDEX, 277 


£30 
AM  0 


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"  31n  tfre  beginning: 
©oa  createn  tfje  fceatien  anD  tfje  eartf)." 

GENESIS  i.  1. 


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csR  2 


ANALYSIS    OF    INTRODUCTION 


H 
CJ 
& 

Q 
O 


I.  ORIGIN  OF  THE  EARTH  ACCORDING  TO  THE  NEBU- 
LAR HYPOTHESIS. 

II.  SCENIC  DESCRIPTION. 
III.  DEFINITION  OF  GEOLOGY. 

i.  THE  SOLID  SHELL. 


IV.  THE     EARTH'S 
CRUST. 


V.  METHODS  OF 
GEOLOGIC 
STUDY. 


2.  PROOF  OF 

THE 

INTERNAL 
HEAT  OF 

THE 


1.  Temperature. 

2.  Artesian  Wells. 

3.  Hot  Springs. 

4.  Elevations  and  De- 

pressions. 

5.  Volcanoes. 


EARTH.     [6.  Earthquakes. 

1.  NATURE'S  LAWS  UNIVERSAL. 

2.  SEDIMENTARY  ROCKS. 

3.  TEACHINGS  OF  SED.  ROCKS. 

4.  IGNEOUS  ROCKS. 

5.  TEACHINGS  OF  IG.  ROCKS. 

6.  FOSSILS. 

7.  TEACHINGS  OF  FOSSILS. 

8.  GLACIERS. 

g.  TEACHINGS  OF  GLACIERS. 
a.  Caves. 


ro.  CHRONOLOGY. 


b.  Lake-bottoms. 

c.  Scottish     Illus- 

trations. 


INTRODUCTION. 

The  Origin  of  the  Earth's  Crtist  according 
to  the  Nebtiiar  'Hypothesis .*— Our  earth  was  once, 
doubtless,  a  glowing  star.  In  that  far  off  beginning  it 
shone  as  brilliantly  as  do  now  the  sun  and  the  fixed 
stars.  In  process  of  time  it  cooled  from  a  gaseous  to  a 
liquid  form.  It  then  assumed  a  spherical  figure  in 
obedience  to  the  same  familiar  laws  of  force  which 
round  a  drop  of  dew.  Its  atmosphere  comprised  not 
only  the  gases  that  compose  our  present  atmosphere, 
but  all  the  oxygen  and  carbon  now  locked  in  the  rock 
and  coal  masses  of  the  earth — vast  quantities  of  min- 
eral matter  vaporized  by  the  fierce  heat,  and,  in  the  form 
of  superheated  steam,  all  the  water  which  now  fills  the 
ocean.  The  air,  thus  dense  with  moisture  and  poison- 
ous metallic  vapors,  rested  on  a  seething  ocean  of  fire. 
Ages  passed,  and  the  earth,  radiating  its  heat  into  space, 
and  thus  cooling,  began  to  show  on  its  surface  patches 
of  solid  substance,  like  the  floating  films  that  first  appear 

*  See  Fourteen  Weeks  in  Astronomy,  p.  282.    THE  NEBULAK  HYPOTHESIS. 


18  GEOLOGY. 

on  water  as  it  passes  into  ice.  These,  gradually  combin- 
ing, formed  at  last  a  thin -crust  over  the  entire  exterior. 
This  was,  however,  constantly  rent  asunder  by  eruptions 
from  the  molten  mass  beneath.  Huge  crevices  were 
opened,  and  torrents  of  liquid  lava,  ejected  from  the 
cracks  and  seams,  were  poured  in  fiery  floods  over  the 
scarcely  solid  crust.  The  surface,  arid  and  burning, 
bristled  with  ragged  eminences,  or  was  furrowed  with 
enormous  clefts  and  cracks.  But  the  earth  had  ceased 
to  shine  as  a  star,  and  henceforth  was  itself  to  be 
lighted  and  at  last  heated  from  other  bodies.  As  the 
globe  continued  to  cool,  a  time  arrived  when  the  heat 
was  not  sufficient  to  support  the  water  in  the  form  of 
vapor.  Under  the  tremendous  pressure  of  the  dense 
atmosphere,  the  steam  was  precipitated,  boiling  hot, 
upon  the  heated  earth  below.  Eevaporized,  it  ascended 
again  only  to  be  condensed  and  returned  as  rain.  This 
process,  long  continued,  cooled  the  earth  yet  more  rap- 
idly. The  crust,  shrinking  and  cracking  as  it  hard- 
ened, became  still  more  uneven  with  wrinkles  and  folds, 
yawning  gulfs  and  fissures.  The  hot  rain  falling  on 
the  volcanic  peaks,  the  torrents  which  poured  down  the 
mountain  sides  and  through  the  valleys,  all  combined 
to  dissolve  the  rock  and  sweep  the  sediment  into  the 
deeper  hollows.  The  crust  had  not  yet  attained  the 
consistency  necessary  to  resist  the  pressure  of  the  heated 
gases  and  liquids.  Hence,  in  this  manner  also,  enor- 
mous dislocations  were  made,  whose  folds  and  uplifts 
with  deep  gulfs  and  belching  lavas  denoted  terrific 
convulsions.  Thus  a  fierce  conflict  was  raging  between 
fire  and  water.  At  last  the  water  triumphed,  and  the 
ocean  became  universal.  A  hot,  muddy,  shallow  sea 


INTRODUCTION.  19 

surged  round  the  earth  from  pole  to  pole.  There  being 
no  dry  land  to  divert  its  course,  a  constant  trade- wind 
must  have  swept  over  this  primitive  ocean  spanning  the 
globe. 

'  Astronomy  teaches  us  the  probable  origin  of  our  globe. 
As  soon  as  the  crust  began  to  be  formed  by  the  mingled 
action  of  lire  and  water,  Geology  steps  in  to  explain  the 
phenomena.  In  this  vague  and  nebulous  border-land  the 
two  sciences  meet.  From  that  time  we  find  that  the 
earth  entered  on  a  regular  series  of  progressive  revolu- 
tions which  gradually  fitted  it  for  the  introduction  of  life. 

The  Mosaic  Account  of  the  Creation  informs 
ns  that  "  the  earth  was  at  first  without  form  and  void ; 
find  darkness  was  upon  the  face  of  the  deep."  With  the 
first  motion  of  nebulous  matter  light  was  developed,  or, 
in  the  nervous  language  of  Scripture — "  God  said,  Let 
there  be  light."  Thus  ended  the  work  of  the  first  day.* 


*  The  word  "day"  is  of  course  considered  not  as  a  literal  day,  but  as  sym- 
bolical of  a  long  period  of  time— ages,  during  which  God  was  fitting  this  earth 
as  a  home  for  man.  The  idea  of  exact  days  of  twenty-four  hoars  each  is  neither 
required  by  the  original  nor  by  the  scope  of  the  narration.  The  word  "day1' 
itself  is  used  in  four  senses  in  the  description.  The  Christian  fathers  did  not 
interpret  it  as  a  common  clay.  Augustine,  in  the  fourth  century,  called  the 
days  of  creation  "  ineffable  days,"  and  described  them  as  "  alternate  births  and 
pauses  in  the  work  of  the  Almighty— the  boundaries  of  periods  in  the  vast 
evolution  of  the  worlds."  How  glorious  the  idea  which  we  here  obtain  of. 
God,  as,  through  measureless  ages  in  which  he  is  rich,  resting  not,  hasting 
not,  but  slowly  and  by  the  steady  operation  of  His  own  laws,  He  works  out 
to  the  finest  detail  His  mighty  thought  of  a  world.  Moses  gives  but  the  grand 
outline  of  this  creative  act,  an  outline  which  Geology  is  filling  up  rapidly  and 
surely.  The  Mosaic  account  is  a  hymn,  full  of  poetry  and  grandeur,  not  a 
close,  exact,  scientific  record  of  events.  Yet  its  truths  were  inspired  by  the 
eame  God  who  made  the  world.  As  such  we  receive  the  records  of  both  rev- 
elation and  nature,  and  gladly  notice  their  harmony  in  all  their  grand  teachings. 
As  yet  Geology  is  in  its  infancy,  and  we  often  are  able  only  to  suggest  and 
intimate  what  may  hereafter  be,  firmly  believing  that  God's  truth  must  stand, 
•whether  it  be  revealed  in  the  rock  or  in  the  book. 


20  GEOLOGY. 

On  the  second,  the  firmament  or  atmosphere  was  formed, 
separating  the  clouds  above  from  the  sea  below,  which, 
as  the  revelations  of  both  the  rock  and  the  book  teach 
us,  as  yet  covered  the  entire  earth.  This  was  the  work 
of  the  second  day,  that  long  era  of  cooling  and  consolida- 
tion that  separated  the  formless  period  of  chaos  from  th 
birth  of  the  continents. 

SCENIC  DESCRIPTION.- Let  us  imagine  the 
scenery  of  that  primitive  period.  A  dark  atmosphere  of 
steam,  vapor,  and  sulphurous  clouds  which  conceals  the 
face  of  the  sun,  and  through  which  the  light  of  moon  or 
star  never  penetrates ;  an  ocean  of  boiling  water,  heated 
at  a  thousand  points  from  the  central  fire ;  low,  half- 
molten  islands,  dim  through  the  fog,  and  scarcely  more 
fixed  than  the  waves  themselves  that  heave  and  tremble, 
lashed  into  fury  by  perpetual  tempests ;  roaring  geysers, 
that  ever  and  anon  throw  up  intermittent  jets  of  boil- 
ing water  and  steam  from  these  tremulous  lands.  In 
the  dim  horizon  the  red  gleam  of  fire  shoots  forth  from 
yawning  chasms,  and  fragments  of  molten  rock  with- 
clouds  of  ashes  are  borne  aloft ;  incessant  flashes  of  light- 
ning evoked  by  the  vast  chemical  changes  which  are 
taking  place,  dart  to  and  fro,  shedding  a  lurid  glare 
upon  the  seething  ocean-cauldron  beneath ;  while  bursts 
of  echoing  thunder,  peal  on  peal,  complete  the  grand  but 
awful  picture. 

•Geology  (ge  the  earth,  and  logos  a,  discourse)  may  be 
defined  as  the  history  of  the  earth's  crust  as  taught  by  its 
rocks  and  fossils. 


1  X  T 11  O  J)  U  C  T 1  O  X.  ,-1 

2?ie  JZarffi's  Crust.  — This  is  evidently  thickening 
from  age  to  age  as  the  cooling  process  goes  on.  Our 
examination  of  it  is  very  superficial,  extending  down- 
ward not  more  than  ten  miles.  On  a  terrestrial  globe, 
eighteen  inches  in  diameter,  the  deepest  wells,  mines, 
and  valleys  would  be  exaggerated  by  a  delicate  scratch 
upon  the  varnish  with  a  pin.  It  is  generally  believed, 
however,  that  the  solid  shell  is  not  over  fifty  miles  in 
thickness,  and  that  the  interior  is  still  a  molten  mass. 
The  facts  upon  which  this  opinion  rests  are  as  follows : 

(1.)  THE  TEMPERATURE  INCREASES  AS  WE  DESCEND. 
— The  rate  varies  in  different  localities,  but  is  always 
over  1°  F.  for  every  hundred  feet.  At  fifty  miles  this 
would  give  a  temperature  of  at  least  3000°  F.,  sufficient 
to  melt  the  most  refractory  rocks.*  Instances  illustrat- 
ing this  increase  of  heat  abound  in  all  parts  .of  the  world 
— in  frigid  Siberia,  in  temperate  Germany,  and  in  tropi- 
cal Africa.  At  a  depth  of  fifty  or  sixty  feet  in  our  lati- 
tude, there  is  a  uniform  temperature  unaffected  by  the 
vicissitudes  of  the  seasons,  and  a  half  mile  below  us  there 
is  summer  heat  the  year  round.  In  a  tin  mine  at  Eed- 
ruth,  Cornwall,  1800  feet  deep,  there  is  a  constant  tem- 
perature of  100°,  equal  to  that  of  a  hot  July  day.  The 
miners,  it  is  said,  cannot  endure  their  clothing,  and  are 
often  compelled  to .  ascend  part  way,  and  plunge  into 
pools  of  the  cooler  water,  in  order  to  continue  their 
labor.  Similar  difficulties  also  are  already  experienced 
in  some  of  the  silver  mines  of  the  west. 

(2.)  ARTESIAN  WELLS  FURNISH  WARM  WATER. — The 
hospital  at  Grenelle  is  heated  by  water  from  an  Artesian 

*  Granite  liquefies  sooner  than  soft  iron,  or  at  a  temperature  of  about  2,400°. 


»8  GEOLOGY. 

well  1800  feet  deep.  At  Wurtemburg,  large  manufac- 
tories are  warmed  in  the  same  manner,  the  water  being 
conducted  through  the  buildings  in  metallic  pipes.  In 
the  Garden  of  Plants,  in  Paris,  the  pipes  are  laid  in  the 
soil ;  and  at  Erfurt,  Saxony,  a  salad  garden  is  thus  made 
to  yield  its  proprietor  an  income  of  $60,000  per  annum. 
The  well  at  Louisville,  Ky.,  furnishes  water  of  a  steady 
temperature  of  76^°,  and  the  one  at  Charleston,  1250 
feet  deep,  water  of  87°. 

(3.)  HOT  SPRINGS  AND  GEYSERS.— One  of  the  former 
in  Arkansas  has  a  temperature  of  180°.  The  geysers  of 
Iceland  and  California  are  fountains  of  boiling  water. 
The  great  geyser  throws  a  column  of  mingled  steam  and 
water,  eight  yards  in  diameter,  to  a  height  of  150  feet. 
Near  the  Sah watch  River,  Col.,  is  an  immense  spring  so 
hot  that  the  hunters  sometimes  cook  their  provisions 
in  it. 

(4.)  ELEVATIONS  AND  DEPRESSIONS  OF  THE  EARTH'S 
CRUST. — The  land  in  various  places  has  been  uplifted  or 
depressed,  either  by  convulsive  throes  or  by  a  slow  move- 
ment continued  through  centuries.  This  indicates  that 
the  ground  on  which  we  tread  has  not  an  unyielding 
support. 

(5.)  VOLCANOES. — These  throw  up  great  masses  of  lava, 
which  is  merely  molten  rock.  There  are  estimated  to  be 
over  300  volcanoes  which  are  either  constantly  or  occa- 
sionally active.  The  amount  of  melted  matter  they  eject 
is  enormous.  Two  streams  of  lava  flowed  from  Skaptar 
Jokul,  a  crater  in  Iceland,  in  1783 — one  fifty  miles  long 
and  twelve  broad,  the  other  forty  miles  long  and  seven 
broad ;  each  was  one  hundred  feet  deep.  When  we  think 
of  such  fiery  torrents,  and  that  the  lava  everywhere  is 


INTRODUCTION.  S3 

essentially  the  same  in  its  composition,  we  can  but  con- 
sider the  interior  of  the  earth  as  a  melted  mass,  and  the 
volcanoes  as  the  chimneys  of  this  huge  central  furnace. 

(6.)  EARTHQUAKES. — Within  the  past  fifty  years,  over 
2,000  earthquake  shocks  have  been  recorded.  They  are 
accompanied  by  volcanic  eruptions,  jets  of  boiling  water, 
and  heated  gases.  The  only  rational  explanation  is  that 
they  are  produced  by  tidal  waves  or  some  terrific  convul- 
sion in  the  fiery  ocean  beneath. 

, 
MetJ&ds  of  Geological  Study. — UNIFORMITY  OF 

•"NATURE.— The  earth  is  a  microcosm — the  universe  in 
miniature.  The  laws  which  govern  our  world  govern 
all  worlds.  The  elements  of  matter  of  which  it  is  com- 
posed are  the  same  as  those  which  make  up  the  farthest 
star  in  space.  The  earth,  therefore,  as  Prof.  Dana  beau- 
tifully says,  though  but  an  atom  in  immensity,  is  immen- 
sity itself  in  its  revelations  of  truth  ;  and  science,  though 
gathered  from  our  small  sphere,  is  the  deciphered  science 
of  all  spheres.  As  this  world  thus  reveals  to  us  the 
laws  of  other  worlds,  so  the  present  time  makes  known 
to  us  the  laws  of  past  time.  The  geologist  believes 
in  the  unchangeableness  of  God's  laws.  All  results  are 
brought  about  by  established  methods.  The  same  effects 
are  always  produced  by  the  same  causes.  The  motions 
of  the  heavenly  bodies,  the  principles  of  heat,  electricity, 
chemical  affinity,  etc.,  are  the  same  now  as  they  have 
been  from  the  beginning.  The  geologist  sees  God  work- 
ing in  nature  through  the  uncounted  ages  of  the  past  as 
He  works  to-day,  not  fitfully,  but  uniformly  developing 
the  mighty  plan  of  the  universe.  Thus  a  knowledge  of 
the  present  is  the  magic  key  whereby  the  geologist  un- 


&£  GEOLOGY. 

locks  the  history  of  the  past.    Let  us  notice  a  few  of  the 
practical  applications  of  this  principle. 

Sedimentary  ffocfcs. —  The  rain- which  falls  on 
the  hills  runs  down  every  slope,  washing  the  soil  into 
the  brooks  and  rivers,  thence  to  the  lake  or  sea.  It  is 
there  deposited  as  a  soft  mud  or  sediment  in  horizon- 
tal layers  or  strata  (singular,  stratum).  The  process  is 
necessarily  slow,  but  uninterrupted.  Year  after  year, 
century  after  century,  adds  layer  on  layer,  the  more 
recent  deposits  concealing  the  more  ancient.  If  we 

FIG.  2. 


Ripple  Marks. 


visit  the  sea-shore,  we  shall  see  the  fine  sand  washed  up' 
by  the  waves,  and  spread,  layer  upon  layer,  in  a  similar 
manner,  each  wave  rippling  its  tiny  ridges,  and  covering 
.others  beneath  its  shifting  sands.  The  geologist  exam* 
ines  the  solid  rocks,  and  finds  strata  composed  of  fine 
sediment  arranged  in  layers,  with  oftentimes  ripple  marks 
curving  the  surface,  appearing  as  distinct  as  if  the  tide 
had  just  ebbed.  He  finds  rocks  presenting  the  look  of 


INTRODUCTION.  86 

half-dried  mud  from  which  the  water  had  been  evapo- 
rated but  yesterday,  leaving  cracks  and  even  prints  of 
rain-drops  so  clearly  denned  that  one  can  tell  from  what 
direction  the  storm  came  which  fell  on  those  mud  flats 
of  the  olden  time.  (See  Fig.  3.)  He  notices  other  strata 

FIG.  3. 


a.  Modern  impressions  of  rain-drops. 

b.  Carboniferous  impressions  of  rain-drops. 

composed  of  sand,  gravel,  or  round  water-worn  pebbles, 
such  as  are  now  seen  along  the  shore  of  river  or  lake 
among  swiftly  moving  waters.  Again  he  discovers  banks 
of  sand  or  clay  where  the  process  of  rock-making  is  still 
progressing,  and  the  material  is  in  all  stages  of  harden- 
ing. He  therefore  decides  that  all  similar  stratified  rocks 
have  been  formed  by  the  action  of  water,  and  hence  calls 
them  sedimentary. 

TEACHINGS  OF  THE  SEDIMENTAKY  ROCKS. — The  water 
records  the  history  of  the  land.    Not  only  is'  the  inani- 
mate dust  of  earth  carried  into  the  vast  storehouse  of 
the  sea,  but  there  lie  millions  of  shells  of  every  shape 
2 


SO  GEOLOGY. 

and  hue  ;  there,  into  the  soft,  oozy  bottom  settle  the 
remains  of  countless  fishes  which  have  thronged  the 
waters  ;  thither  float  leaves  and  reeds,  and  trees  torn 
up  by  the  tempest,  swept  seaward  from  every  shore; 
there  sink  skeletons  of  sea-fowls,  exhausted  land-birds, 
and  animals  borne  to  the  sea  by  rapid  rivers ;  ships  with 
their  unclaimed  cargoes,  gone  on  their  final  voyage,  and 
in  harbor  at  last ;  drowned  mariners  lying  in  their  quiet 
graves  unconscious  of  the  fiercest  storm  that  sweeps 
above  them — all  these  varied  relics  are  slowly  buried  by 
the  ever-settling  sediment.  The  bottom  of  the  ocean  is 
a  cemetery  in  which  lie  the  dead  from  the  three  king- 
doms of  Nature.  Layer  by  layer  are  gathered  the  re- 
mains of  each  passing  year,  the  history  of  every  age 
being  thus  deposited  and  built  into  the  very  founda- 
tions of  the  earth.  Could  we.  gain  access  to  this  sea- 
bottom,  we  should  find  revealed,  with  each  layer  turned 
up  by  our  spade,  a  fresh  page  of  the  history  of  the  world. 
The  ocean  is  now  making  up  a  continuation  of  this  his- 
tory. The  geologist  is  reading  the  earlier  volumes  in  the 
stratified  rocks,  the  sea-bottom  of  the  olden  time. 

Igneous  ffioc&s.  —  The  geologist  watches  the  action 
of  volcanoes  and  earthquakes  at  the  present  day.  He 
notices  that  rocks  of  various  consistency  and  character 
are  formed  from  the  cooling  lava,  and  that  stratified  or 
sedimentary  rocks  are  displaced  and  rent,  the  fissures 
being  filled  with  injected  matter.  In  the  earth's  crust, 
at  various  places,  the  exact  counterparts  of  these  rocks 
and  these '  displacements  occur.  The  rocks  are  not  ar- 
ranged in  layers,  but  piled  up  in  mountain  masses,  break- 
ing through  the  stratified  rocks,  tilting  and  throwing 


INTRODUCTION.  27 

them  out  of  their  original  positions.  The  observer  has 
no  more  difficulty  in  accepting  the  evidence  that  the 
unstratified  rocks  give  of  former  igneous  action  and  con- 
vulsion than  in  admitting  the  eruptions  and  earthquakes 
of  Etna  and  Vesuvius. 

TEACHINGS  OF  THE  IGNEOUS  ROCKS.— The  geologist 
calls  all  rocks  which  indicate  the  action  of  fire  igneous, 
and  ascribes  dislocations  of  strata  and  filling  up  of  cracks 
with  igneous  products  to  the  operation  of  ancient  vol- 
canoes and  earthquakes.  If  he  is  not  correct  in  his  con- 
clusions, then  Nature  is  not  uniform,  and  is  making  the 
same  kind  of  rock  on  one  day  by  fire  and  on  another  by 
water,  and  thus  all  the  history  of  the  past  is  a  delusion. 

\  * 
Fossils  (fossilis,  dug  up)  is  a  name  applied  to  all 

animal  or  vegetable  remains  which  are  found  embedded 
in  the  rocks  oil  the  earth's  crust.  What  we  have  already 
said  concerning  the  sedimentary  rocks  shows  us  how 
fossils  arc  now  forming  and  have  been  formed  in  all 
time.*  As  the  autumnal  leaf  drops  into  the  stream,  and 


*  These  remains  were  known  to  the  ancients,  and  considered  "freaks  of  Na- 
ture." Tradition,  which  attributed  to  Achilles  and  other  heroes  of  the  Trojan 
war  a  height  of  twenty  feet,  is  traceable,  no  doubt,  to  the  discovery  of  ele- 
phants' bones  near  their  tombs.  Thus,  for  example,  we  are  assured  that,  in 
the  time  of  Pericles,  in  the  tomb  of  Ajax  was  found  a  knee-bone  of  that  hero 
which  was  as  large  as  a  dinner  plate.  It  was,  probably,  the  fossil  knee-bone 
of  an  elephant.  The  Spartans  prostrated  themselves  befqre  the  remains  of 
one  of  these  animaly,  in  which  they  thought  they  recognized  the  skeleton  of 
Orestes.  Some  bones  of  a  mammoth  found  in  Sicily  were  considered  as 
having  belonged  to  Polyphemus.  Even  the  learned  of  a  later  day  were  not 
exempt  from  these  blunders.  Felix  Plater,  Professor  of  Anatomy  at  Basle,  in 
1517,  referred  the  bones  of  an  elephant  discovered  at  the  roots  of  a  tree  torn  up 
by  the  wind  near  Lucerne,  to  a  giant  at  least  nineteen 'feet  high.  He  even 
restored  it  in  a  sketch  which  was  long  preserved  in  the  college  at  Lucerne. 
In  England,  similar  bone3  \verc  regarded  as  those  of  the  fallen  angels  !  When 
geology  first  began  to  be  studied,  people  generally  considered  the  deposition  of 
fossils  ns  having  a  connection  with  Noah's  flood.  Cuvier  found  the  skeleton 


28  GEOLOGY. 

becomes  imbedded  in  its  mud — as  the  trees  of  the  forest 
are  borne  down  by  the  flooded  river  and  are  ultimately 
entangled  in  the  sediment  of  its  estuary — as  the  coral 
reef  and  shell-bed  are  gradually  increasing  and  growing 
as  it  were  into  limestone  before  our  eyes — as  the  skele^ 
tons  of  animals  are  drifted  by  the  tide  and  fall  to  the 
sea-bottom  or  sink  into  rivers  and  marshes,  and  are  th&s 
preserved  from  rapid  decay — so  in  all  time  past  have 
similar  agencies  been  at  work ;  here  preserving  the  bro- 
ken twig  and  the  fallen  forest,  there  the  coral  reef  and 
th'e  shell-bed,  and  anon  the  remains  of  animals  that  were 
borne  by  rivers  from  the  land,  or  drifted  by  the  Waves  on 
the  muddy  sea-shore.  > 

TEACHINGS  OF  THE  FOSSILS. — Digging  in  me  soil,  we 
find  a  bone.  We  examine  it.  It  is  one  of  t^e  vertebra) 
of  a  horse.  We  believe  it  to  be  real.  It  is  not  a  "freak 
of  Nature,"  but  was  once  part  of  a  living  l^rse.  We  dis- 
cover some  strange  fossil  bone,  and  are  1M  irresistibly  to 
a  similar  conclusion.  The  skilful  geologist,  understand- 
ing perfectly  the  relation  tyiat  exists  bo/ween  the  different 
parts  of  the  animal  frame,  whereby  each  portion  subserves 
its  part  toward  the  development  of/ life  and  its  functions, 
can  restore  the  entire  form,  and  even  indicate  the  habits 
of  the  creatures  that  formerly^peopled  our  globe.  For 
example,  a  sharp  claw  belongs  to  a  flesh-eating  animal 
with  sharp  cutting  molars ;  a  hoof,  to  a  grazing  species 

of  a  gigantic  salamander  preserved  as  a  specimen  of  the  accursed  race  swal- 
lowed up  by  the  Deluge. 

When  we  speak  of  fossils  being  converted  to  stone,  we  do  not  mean  that  the 
particles  of  the  original  substance  have  been  changed  to  stone",  but  that,  as  they 
decayed,  they  have  been  replaced  by  stone.  This  is  true,  however,  only  of  the 
fossils  of  the  older  formations.  The  new  ones  retain  their  original  substance. 
Shells  of  the  Tertiary  Period  can  often  scarcely  be  distinguished  from  modern 
ones,  while  sharks'  teeth  exhibit  their  enamel  intact. 


INTRODUCTION.  29 

with  broad 'molars.  Knowing,  too,  the  conditions  neces- 
sary to  the  life  of  such  animals,  he  can  also  decide  upon 
the  climate,  food,  etc.,  which  then  existed.  Agassiz,  from 
a  single  scale,  reconstructed  an  entire  fish.  Subsequent 
discoveries  proved  his  idea  to  be  singularly  accurate.  The 
restoration  of  the  megalosaur  by  Hawkins  is  a  remarkable 
instance  of  a  similar  character.  (See  Fig.  83.) 

We  visit  the  sea-shore,  and  gather  shells  along  the 
£beach..  On  digging,  we  discover  others  buried  from 
sight,  l^ese  are. filled  with  damp  sand,  which  perfectly 
retains  their  impress.  In  the  quarry  among  the  layers 
of  sedimentary  rocks,  we  find  similar  fossil  shells.  They 
are  certainly  the  remains  of  ancient  life,  and  must  have 
existed  when  the  rock  was  in  process  of  formation.  They 
prove  the  rock  to  have  been  once  under  water.  If  the 
shells  are  marine,  it  was  the  sea ;  if  fresh  water,  a  lake  or 
river ;  if  intermediate,  an  estuary.  The  testimony  is  as 
conclusive  a§  ilVvve  had  lived  by  that  ancient  shore,  and 
ha$f 'Witnessed  their  growth,  decay,  and  entombment  in 

*%<*• 

In  certain  clay  beds  of  England,  shells  are  found  of 
species  now  existing  only  in  polar  seas.  We  thence  infer 
that  when  that  clay  was  deposited,  and  those  shells  were 
inhabited,  a  climate  similar  to  that  of  Greenland  must 
have  prevailed  in  British  latitudes.  Remains  of  the  rein- 
deer and  musk  ox  occur  in  France..  These  indicate  a 
former  Arctic  temperature,  unless  we  are  to  suppose  that 
the  habits  of  those  animals  have .  entirely  changed  since 
the  time  of  their  existence  in  southern  Europe. 

Action  of  Glaciers  (Gla'-seers).—  Philosophers 
have  carefully  studied  the  effects  of  .moving  masses  of 


30  GEOLOGY. 

ice.  They  have  seen  how  the  glacier  pushes  its 
down  the  Alpine  valley,  grinding,  rounding,  smoothing, 
and  marking  the  rocks  over  which  it  passes,  and  de- 
positing at  the  bottom  its  burden  of  debris.  They  have 
\vatched  the  glaciers  of  polar  regions  collecting  on  the 
sea-shore  until  at  last  great  mountains  of  ice  break 
loose  and  float  southward.  They  have  seen  these  ice- 
bergs grounding  and  melting  in  a  more  genial  clime, 
where  they  finally  drop  their  load  of  rocky  fragments  on 
the  sea-bottom. 

TEACHINGS  OF  THE  GLACIERS. — The  geologist,  in  re- 
gions now  far  removed  from  glacial  action,  finds  the 
lower  extremities  of  mountain  glens  and  valleys  heaped 
with  mounds  of  sand  and  gravel,  and  the  rocky  surface 
marked  with  parallel  grooves,  such  as  no  known  agency 
except  the  glacier  ever  produces.  Resting  on  the  lower 
hills  and  scattered  over  valley  and  plain  teyond,  he  sees 
great  bowlders  of  a  weight  far  exceeding  tne  transporting 
power  of  water,  miles  removed  from  their  parent  rocks, 
and  with  their  sides  smoothed  and  marked.  He  ascribes 
these  results  to  glaciers  and  icebergs.  He  assumes  that 
these  mountains  were  once  covered  with  snow,  these 
glens  once  filled  with  glaciers,  and  that  these  lower 
lands  were  the  bottoms  of  seas  on  which  floating  ice- 
bergs grounded,  and,  melting,  left  their  loads  of  rocky 
debris. 

Cfironotogy. — Many  geological  facts  aid  in  deter- 
mining the  relation  of  different  events  in  respect  to  time. 
The  following  instances  illustrate  the  method : 

CAVES.  —  In  certain  caves  the  bones  of  various  ani- 
mals are  found  embedded  in  a  calcareous  deposit,  which 


INTRODUCTION.  81 

has  accumulated  on  the  floor  by  water  slowly  dripping 
from  the  roof.  Many  of  the  bones  have  been  gnawed,  and 
the  hollow  ones  split  lengthwise.  The  geologist  ascribes 
the  former  to  den-frequenting,  carnivorous  animals  like 
the  hyena,  and  the  latter  to  a  marrow-sucking  race  of 
men.  This  conclusion  is  still  further  substantiated  by 
finding  traces  of  the  hyena,  and  also  stone-hatchets, 
ashes,  and  charred  sticks  of  wood.  Man,  alone,  lights  a 
fire.  Hence  we  are  as  sure  of  the  existence  of  a  rude 
cave-dwelling  tribe  of  men  as  if  we  had  witnessed  their 
grim  countenances  lighted  up  by  the  fires  of  which 
those  fragments  were  the  latest  embers.  The  .hyena  and 
the  cave-dwellers  lived  at  the  same  epoch.  The  deeper 
the  layer  the  older  the  remains.  If  we  can  only  deter- 
mine the  rate  at  which  the  soil  accumulates,  we  can 
estimate  with  some  degree  of  accuracy  their  antiquity. 

LAKE-BOTTOMS. — We  drain  a  level,  basin-shaped  mead- 
ow. The  general  form  and  location  suggest  the  idea 
that  it  may  have  been  anciently  the  site  of  a  lake. 
The  moment,  however,  we  dig  below  the  surface,  the 
geologic  evidence  converts  the  inference  into  a  matter 
of  certainty.  We  pass  through  first  the  soil,  next  a  layer 
of  peat,  then  one  of  marl,  and  lastly,  one  of  clayey  sedi- 
ment. In  the  peat  we  find  antlers  of  deer  and  bones  of 
oxen ;  in  the  marl,  fresh-water  shells ;  and  in  the  sedi- 
ment, a  log  hollowed  out  into  a  rude  canoe.  Here  we 
have  the  whole  history  of  the  lake,  and  in  reading  it  we 
can  trace  the  successive  stages  as  clearly  as  if  we  had 
lived  by  its  shores  from  the  time  it  was  a  sheet  of  shal- 
low water  to  the  hour  of  its  final  obliteration.  First, 
the  open  lake,  over  which  the  simple  native  paddled  his 
rude  canoe ;  second,  the  shallower  sheet,  where  fresh- 


82  GEOLOGY. 

water  shell-fish  luxuriated  in  myriads,  and  succeeded 
each  other,  generation  after  generation ;  third,  the  peat 
marsh,  over  which  deer  and  oxen  occasionally  ventured, 
and  were  mired;  and  fourth,  the  level  meadow,  when 
the  site  became  too  dry  for  the  peat-forming  plants  to 
nourish.  We  have  no  exact  chronology  for  these  events, 
and  can  only  decide  their  order.  The  canoe  may  have 
sunk  one  thousand  or  five  thousand  years  ago,  for  aught 
we  know.  If,  however,  we  can  form  some  idea  of  the 
rate  at  which  the  sediment  was  deposited,  or  the  marl 
and  the  peat  formed,  we  can  then  judge  somewhat  of  its 
antiquity. 

SCOTTISH  ILLUSTRATIONS. — Such  ancient  lake-bottoms 
are  seen  in  the  Lowlands  of  Scotland.  The  geologist 
finds  below  the  peat-bog  the  bones  of  horse,  pig,  deer, 
dog,  and  man ;  deeper  still,  the  Eoman  eagle  or  sword ; 
next,  the  bones  of  the  wild  ox,  bear,  wolf,  beaver ;  then 
the  wooden  canoe;  below  the  marl,  bones  and  antlers  of 
the  gigantic  Irish  elk,  and  tusks  of  the  great  mammoth.; 
and  at  the  bottom  the  solid  rock,  strewn  with  ice-borne 
blocks — the  original  bed  of  the  lake  when  its  waters  were 
first  gathered  together.  Occasionally,  also,  raised  mounds 
of  piles,  plank,  branches,  stones,  and  other  material  are 
laid  bare.  These  were  the  foundations  of  the  lake-dwell- 
ings of  former  days,  raised  by  primitive  men  for  their 
defence.  They  reveal  stone  hammers,  flint  spear-heads, 
split  bones,  and  fragments  of  rude  potters-ware.  What 
a  marvelous  history  we  read  from  these  records  of  Na- 
ture !  In  the  beginning  there  is  the  gleaii  sheet  of 
water  rippling  in  the  European  landscape — lor  Great 
Britain  has  not  yet  been  separated  from  the  -continent 
—surrounded  by  forests  of  pine,  birch,  and  willow.  The 


INTRODUCTION.  83 

climate  is  severe,  and  the  woolly-haired  mammoth 
tramps  through  the  overhanging  bushes  down  to  the 
water's  edge.  Centuries  pass.  Eeindeer  and  Irish  elk 
betake  themselves  to  the  water  in  summer,  and  sink  into 
its  miry  depths,  or  seek  to  cross  its  frozen  crust  during 
the  winter's  snow,  and  are  buried  beneath  the  treacher- 
ous surface.  Ages  roll  on.  The  climate  becomes  milder, 
and  Britain  is  detached  from  the  continent.  The  lake 
is  gradually  becoming  shallow ;  reeds  and  bulrushes  en- 
croach upon  its  margin ;  oak  clumps  adorn  its  banks, 
along  which  prowl  the  wolf  and  bear ;  the  beaver  builds 
his  dam  across  the  entering  stream,  and  the  wild  ox  and 
red  deer  stand  lolling  in  its  cool  waters.  A  race  of  short, 
broad,  round-headed  men  settle  by  the  shore,  pile  the 
mounds  and  wattle  their  simple  lake-dwellings ;  with  fire 
and  stone  adzes  scoop  out  the  oak-trunks  into  canoes, 
spear  the  ox  and  deer  in  the  woods,  and  enjoy  the  com- 
forts of  a  dawning  civilization.  Time  passes.  Still  the 
lake  grows  shallower,  and  its  reedy  margin  broader.  A 
new  race  of  men — taller,  higher-headed,  and  more  nimble 
— take  possession  of  the  scene.  They  settle  the  slopes, 
erect  their  rude  alfars  in  the  oak  clumps,  domesticate  the 
ox,  horse,  and  dog,  and  attempt  a  scanty  cultivation  of 
the  soil.  The  Roman  legions  at  last — we  know  the  date 
of  that  event,  about  two  thousand  years  ago — invade  the 
country,  scatter  the  natives,  and  encamp  by  the  lake. 
They  erect  their  votive  altars,  make  plank  roads  through 
the  marshy  borders,  and  drop  their  implements  and  uten- 
sils by  the  side  of  those  of  the  ancient  Briton.  The  pre- 
historic ages  have  now  passed,  and  we  can  more  easily, 
but  still  somewhat  confusedly,  continue  the  onward  his- 
tory  of  the  fast  lessening  waters.  The  Romans  dis- 


84  GEOLOGY. 

appear.  Celt  and  Saxon  contend  for  the  soil,  and  we 
trace  in  the  uppermost  bog-earths  the  remains  of  ex- 
isting breeds  of  oxen,  sheep,  horses,  pigs,  dogs,  and 
other  domestic  animals,  and  even  implements  of  iron 
belonging  to  successive  stages  of  civilization  down  to 
the  present  time. 


(A    Stone=<l)iscourse.) 


"< oind  this  our  life,  exempt  from  public  haunt, 
Finds  tongues  in  \trees,  books  in  the  running  brooktt 
Sermons  in  f/onefj  and  good  in  everything." 

SHAKESPEARE. 


Geology  (Uthos,  a  stone,  and  logos,  a 
discourse,)  means,  literally,  a  discourse  about  stones.*  It 
treats  of  (1)  the  Composition ,  (2)  the .  Classift ca- 
tion, and  (3)  the  Structure  of  'the  rocks  which  make 
up  the  earth's  crust.  Underneath  the  soil  and  the  sea 
there  is  everywhere  a  rocky  foundation  which  protects 
us  from  the  fiery  interior.  Along  the  sea-shore,  river- 
side, road-cuttings,  etc.,  this  solid  basement  is  exposed 
to  view.  It  is  generally  arranged  in  layers,  sometimes 
loosely,  as  sand,  clay,  or  gravel,  and  sometimes  partly 
hardened  into  stone.  Since  it  passes  thus  insensibly 


*  There  is  no  natural  object  out  of  which  more  can  he  learned  than  out  of 
stones.  They  seem  to  have  been  created  especially  to  reward  a  patient  ob- 
server. Nearly  all  other  objects  in  Nature  can  be  seen,  to  some  extent,  with- 
out patience,  and  are  pleasant  even  in  being  half  seen.  Trees,  clouds,  and 
rivers  are  enjoyable  even  by  the  careless.  But  the  stone  under  the  foot  has 
nothing  for  carelessness  but  stumbling ;  no  pleasure  is  to  be  had  out  of  it,  nor 
food,  nor  good  of  any  kind ;  nothing  but  symbolism  of  the  hard  heart  and 
the  unfatherly  gift.  Yet  do  but  give  it  some  reverence  and  watchfulness,  and 
there  is  bread  of  thought  in  it  more  than  in  any  other  lowly  feature  of  all  the 
landscape.  For  a  stone,  when  it  is  examined,  will  be  found  a  mountain  in 
miniature.  The  fineness  of  Nature's  work  is  so  great  that  into  a  single  block, 
a  foot  or  two  in  diameter,  she  can  compress  as  many  changes  of  form  and  struc- 
ture, on  a  small  scale,  as  she  needs  for  her  mountains  on  a  large  one;  and 
taking  moss  for  forests,  and  grains  of  crystal  for  crags,  the  surface  of  a  stone, 
in  most  cases,  is  more  interesting  than  the  surface  of  a  hill ;  more  fantastic  in 
form  and  inconceivably  richer  in  color.— Ruskin. 


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JfQ  LI  T  HO  LOG  1C A  L      GEOLOGY. 

from  one  stage  of  consolidation  into  another,  the  geolo- 
gist applies  the  term  rock  alike  to  all.  The  desert  of 
Sahara  is  a  sand-rock.  Ice  is  a  rock  as  certainly  as  is 
limestone. 


1     COMPOSITION    OF    THE    MOCKS. 

Rocks  are  composed,  in  general,  of  only  three  common 
minerals—  Quartz,  C2qy,  and  J^ime.  Wherever  you 
stand  on  the  solid  ground,  in  any  country  of  the  globe, 
you  may  be  sure  that  the  rock  under  you  is  mainly 
some  form  or  compound  of  one  or  more  of  these  earth- 
builders.* 


'(,. 


)    SILICA: 


/.  Quartz  (silica,  silex)  is  the  oxide  of  silicon,  a 
rare  non-metallic  substance  known  only  to  the  chemist. 
Silica  is  the  most  abundant  of  all* the  minerals,  compris- 
ing one-half  of  the  earth's  crust.  It  is  so  hard  that  it 
strikes  fire  with  steel,  scratches  glass  like  a  diamond,  and 


*  Since  there  were  so  few  substances,  Nature  seems  to  have  set  herself 
about  making  these  three  as  interesting  and  beautiful  as  she  can.  The  clay, 
being  a  soft  and  changeable  substance,  she  doesn't  take  much  pains  about — she 
only  brings  the  color  into  it  when  it  takes  on  a  permanent  form  on  being  baked 
into  brick.  (Buskin's  statement  does  not  hold  good  in  America.  For  examples, 
the  clays  of  Southern  Virginia  and  North  Carolina  are  beautifully  mottled,  the 
cliffs  at  Gay  Head  present  brilliant  tints,  and  the  porcelain  clays  of  Western 
Kentucky  exhibit  fine  coloring.)  But  the  limestone  and  flint  she  paints  in  her 
own  way,  in  their  native  state ;  and  her  object  in  painting  them  seems  to  be 
much  the  same  as  in  her  painting  of  flowers— to  draw  us,  careless  and  idle 
human  creatures,  to  watch  her  a  little,  and  see  what  she  is  about,  that  being,  on 
the  whole,  good  for  us,  her  children.  To  lead  us  to  do  this  she  makes  picture- 
books  for  us  of  limestone  and  flint ;  and  tempts  us,  like  foolish  children,  as  we 
are,  to  read  her  books  by  the  pretty  colors  in  them.  The  pretty  colors  in  her 
limestone  books  form  those  variegated  marbles  which  all  mankind  have  taken 
pains  to  polish  and  build  with  from  the  beginning  of  time  ;  and  the  pretty 


COMPOSITION     OF    THE     ROCKS.  41 

cannot  be  cut  with  a  knife.  It  has  no  cleavage,*  and 
breaks  into  irregular  fragments  having  a  glassy  lustre. 
It  is  insoluble  in  any  acid  (except  hydrofluoric),  and 
melts  only  in  the  heat  of  the  compound  blow-pipe.  On 

FIG.  4. 


A  Cluster  of  Quartz  Crystals  from  Lake  Superior. 


colors  in  her  flint  books  form  agates,  jaspers,  carnelians,  etc.,  which  men 
have,  in  like  manner,  taken  delight  to  cut  and  polish  and  make  ornaments  of 
from  the  beginning  of  time  ;  and  yet  so  much  of  babies  are  they,  and  so  fond  of 
looking  at  the  pictures  instead  of  reading  the  books,  that  I  question  whether, 
after  six  thousand  years  of  cutting  and  polishing,  there  are  more  than  two  or 
three  out  of  any  hundred  who  know,  or  care  to  know,  how  a  bit  of  agate  or 
marble  was  made  or  painted. — fiuskin. 

*  Cleavage  is  the  property  of  splitting  with  smooth  surfaces  in  certain  fixed 
directions:  Many  crystals  separate  very  easily  in  those  joinings  which  Nature 
has  made. 


42  LITHOLOGICAL      GEOLOGY. 

account  of  its  hardness,  which  resists  the  action  of  the 
elements,  it  comprises  a  large  part  of  ordinary  pebbles, 
sand,  and  much  even  of  the  soil.  It  is  found  in  crys- 
tals of  the  form  shown  in  the  figure.  When  pure,  like 
those  of  other  minerals,  they  are  generally  small,  and 
sometimes  occur  in  beautiful  clusters.  Crystals  of  great 
size,  though  of  inferior  clearness,  are  occasionally  seen. 
Dartmouth  College  cabinet  possesses  a  group  weighing 
147  pounds.  At  Milan  is  a  single  crystal  3|  feet  long  and 
5J  feet  in  circumference,  estimated  to  weigh  870  pounds. 

2.  ffioc/c   Crystal  is  the  clear  crystalline  quartz. 
The  name   is  derived  from  the  Greek   word  krustallos, 
meaning  ice.      The  purest  specimens,  are  often  cut  for. 
jewelry,   and   sold  as   "  white    stone "   and    "  California 
diamonds."      They  are   also   used  for  spectacle  glasses. 
Anciently  they  were  cut  into  vases  and  cups,  some  of 
which  are  still  preserved  as  curiosities.     It  is  said  that 
Nero,  on  learning  of  the  insurrection  which  led  to  his 
fall,  dashed  into  pieces  two  crystal  vases,  one  valued  at 
$3000.     Pure  quartz  sand  is  used  in  large  quantities  for 
making  glass. 

Quartz,  when  colored  by  the  various  metallic  oxides, 
presents  a  bewildering  variety.  The  young  geologist, 
after  having  gathered  a  very  respectable  collection  of 
minerals,  has  often  been  surprised  to  learn  that  he  has 
hardly  passed  outside  of  this  legion  family. 

i 

3.  ffiose  or  ^Pinfc  Quartz  is  rarely  found  as  crys- 
tals, but  generally  as  a  massive  rock.     On  exposure  to 
the  light,  the   color  fades,  but  it  can  be  restored  by 
leaving  the  stone  for  a  time  in  a  damp  place. 


COMPOSITION     OF     THE     ROCKS.  43 

SMOKY  QUARTZ  has  a  dark-brown,  smoky  tint.  It  is 
often  black  and  opaque,  except  in  thin  portions,  which 
are  semi-transparent. 

MILKY  QUARTZ  is  a  milk-white,  opaque,  massive 
variety,  looking  not  unlike  porcelain. 

GRANULAR  QUARTZ  consists  of  small  grains  of  quartz 
cemented  into  a  massive  rock.  It  has  a  texture  similar 
to  that  of  loaf-sugar,  and  oftentimes  crumbles  easily  into 
sand.  It  is  used  for  hearthstones,  furnaces,  etc.,  and, 
when  powdered,  for  making  sand-paper,  glass,  or  pottery. 

/£ .  J~.mel?iysl  has  a  beautiful  purplish  tint  from  the 
oxide  of  manganese,  which  it  contains.  The  name  means 
"  a  preservative  from  intoxication,"  and  was  given  it  from 
a  belief  of  the  ancient  Persians,  that  wine  drank  from  an 
amethyst  cup  lost  its  inebriating  properties. 

5 '.  Chalcedony  is  distinguished  by  its  waxy,  horn- 
like lustre.  It  has  generally  a  white  or  brownish  shade. 
"When  bright  red,  it  is  a  carnelian.  When  brownish  red, 
a  sard.  When  colored  apple-green  with  nickel,  a  chrys- 
oprase. 

6 '.  Agate  is  a  kind  of  chalcedony,  in  which  the  dif- 
ferent shades  of  color  are  arranged  in  parallel  lines — the 
edges  of  the  layers  which  compose  the  stone.  These 
layers  are  very  like  the  coats  of  an  onion,  and  represent 
the  successive  deposits  by  which  the  agate  was  formed. 
They  are  often  so  thin  as  to  number  fifty  within  an  inch. 
When  the  lines  are  zigzag,  it  is  termed  a  fortification 
agate,  from  the  resemblance  to  the  irregular  outlines  of  a 
fortress.  When  the  stripes  alternate,  an  opaque  with  a 


44  LITHOLOGICAL      GEOLOGY. 

transparent  band,  the  stone  is  termed  an  onyx  (onyx,  a 
nail),  from  a  fancied  resemblance  to  the  alternating  lines  ' 
on  the  finger-nail.  When  a  deep  brownish-red  stripe  (a 
sard)  alternates  with  a  white  one,  the  agate  is  called  a 
sardonyx.  When  a  yellowish-brown  oxide  of  iron  is  dis- 
seminated through  the  stone  in  moss-like  forms,  it  is 
termed  a  moss  agate. 

Eeal  cameos  are  cut  from  the  onyx.  The  most  cele- 
brated of  the  ancient  cameos  is  the  Mantuan  vase  at 
Brunswick.  It  was  cut  from  a  single  stone.  It  is  in  the 
form  of  a  cream-pot, 'about  7  inches  high  and  2|  broad. 
On  its  outside,  which  is  of  a  brown  color,  there  are  white 
and  yellow  groups  of  raised  figures,  representing  Ceres 
and  Triptolemus  in  search  of  Proserpine.  The  lines  of 
agates  sometimes  present  a  striking  resemblance  to  vari- 
ous objects.  Some  are  so  remarkable  as  to  be,  without 
doubt,  exceedingly  ingenious  works  of  art.  Thus,  Pliny 
tells  of  an  agate,  belonging  to  Pyrrhus,  in  which  were 
pictured  the  nine  muses,  and  Apollo  in  the  midst  playing 
on  his  lyre.  Agates  are  very  abundant  on  the  shores  of 
Lake  Superior,  and  many  lakes  and  rivers  of  the  west.. 
Externally  the  agate  is  rough,  and  exhibits  no  sign  of 
the  beautifully  varied  appearance  it  will  present  when 
polished.* 

*  AGATE  MANUFACTURE.— The  most  celebrated  agate  quarries  are  at  Ober- 
stein,  Germany.  The  nodules  are  of  an  ashen-gray  color.  After  being  washed, 
they  are  placed  in  a  vessel  containing  honey  and  water,  which,  being  closely 
covered,  is  kept  in  hot  ashes  for  two  or  three  weeks.  The  stones  are  then  taken 
out,  cleansed,  immersed  in  sulphuric  acid,  and  then  roasted  a  second  time  in 
the  hot  ashes.  The  honey,  penetrating  the  pores,  is  carbonized  either  by  the 
long-continued  heat  or  the  action  of  the  acid.  The  depth  of  the  color  depends 
on  the  porosity  of  the  agate!  Some  become  perfectly  black,  others  take  a  rich 
brown  or  chocolate  tint,  some  are  striped  alternately  like  the  onyx,  while 
others  resist  all  attempts  to  change  the  natural  hue.  By  soaking  the  porous 
agates  in  a  solution  of  sulphate  of  iron,  and  then  heating  in  an  oven,  a  fine 


COMPOSITION     OF     THE     ROCKS  43 

7.  J~asper  is  a  dull,  massive  variety  of  quartz,  with 
a  little  clay.  It  has  shades  of  red,  yellow,  brown,  and 
green,  owing  to  the  presence  of  iron  in  different  stages 
of  oxidation.  The  yellow  becomes  red  by  heat,  which 
changes  the  yellow  oxide  of  iron  to  red.  When  the  colors 
are  arranged  in  stripes,  it  is  termed  ribbon  jasper.  It  is 
susceptible  of  high  polish,  and  is  therefore  much  prized 
for  ornamental  purposes.  When  of  a  deep  green,  with 
dark  red  spots,  it  is  named  Uood-stone.  At  Paris  there 
is  a  bust  of  Christ  carved  from  this  stone  in  such  a 
manner  that  the  red  spots  represent  the  drops  of  blood. 
A  hard,  velvet  black  jasper  is  called  the  touchstone.  It  is 
used  for  testing  the  purity  of  gold  alloys.  This  is  done 
by  rubbing  the  alloy  on  the  stone,  and  comparing  the 
color  with  that  of  some  known  alloy.  The  stone  is 
adapted  for  this  purpose  because  of  its  hardness  and 
smoothness,  and  also  because  it  presents  a  good  back- 
ground on  which  to  compare  colors. 

6*.  Opa2  is  a  most  beautiful  variety  of  quartz.  It 
contains  ten  per  cent  of  water,  which  is  combined  with 
the  silica.  It  is  softer  than  quartz,  and,  unlike  it,  is 
easily  soluble  in  a  hot  solution  of  potash.  Its  external 
color  is  a  pure  white,  but  when  broken  it  exhibits  a  play 
of  rich  and  delicate  internal  reflection.  A  kind  called 


carnelian  red  is  produced.  A  blue  color,  which  has  all  the  effect  of  a  turquoise, 
is  also  developed  by  a  process  not  yet  divulged.  By  roasting,  the  natural  colors 
are  heightened  and  rendered  more  permanent.  In  these  various  ways  a  coarse 
and  valueless  stone  may  be  so  changed  as  to  pass  for  a  gem  of  the  first  quality. 
The  agates  are  ground  on  rough  stones,  turned  by  water-power  from  the  numer- 
ous little  brooks  which  abound  in  that  neighborhood,  and  polished  on  soft 
wooden  wheels  with  powder  of  tripoli  (see  page  48)  found  near  by.  Vases,  cup*, ' 
seals,  knife-blades,  agate  mortars  for  the  chemist's  use,  etc.,  are  made  in  such 
abundance  as  to  become  articles  of  commerce. 


Jf(J  LITHO  LO  GICAL       G  E  0  L  0  G  Y. 

hydrophane  is  remarkable  for  becoming  transparent  when 
dipped  into  water.* 

9.  Sandy  'Pebbles,  Grare2,  Cobblestones,  etc., 

consist  largely  of  quartz,  since  it  resists  the  action  of  the 
water  longer  than  other  rock  materials.  The  color  is 
due  to  the  various  oxides  of  iron ;  f  although  it  is  some- 
times a  mere  stain  produced  by  vegetable  matter. 

/#.  Flint  is  a  compact  form  of  quartz  of  various 
colors — white,  brown,  and  even  black.  It.  breaks  into 
fragments  having  a  sharp  edge  and  a  conchoidal  J  sur- 
face. Its  use  formerly  for  gun-flints,  and  by  the  Indians 
for  arrow-heads  is  well  known. 

HOK^STONE  is  an  impure  variety  of  flint,  so  named 
from  its  color  and  appearance.  BuTirstone  is  a  kind  of 
flint  possessing  a  cellular  texture,  which  makes  its  sur- 
face very  rough.  In  many  of  the  best  stones  the  cavities 
equal  the  solid  portions.  It  is  found  in  various-  States 


*  The  same  phenomenon  is  shown  in  an  ox's  eyeball.  When  plunged  into 
•water,  it  vanishes  instantly  from  the  sight.  They  refract  light  at  the  same  angle 
as  water,  and  hence  the  eye  has  no  power  of  distinguishing  them. 

t  Iron  is  Nature's  universal  dye.  Without  it  the  soil  would  be  a  dirty  white— 
the  color  of  snow  in  a  time  of  thaw.  Instead  of  the  pretty  lively  color  of  sand 
and  pebbles,  we  should  see  the  dull  and  somber  hue  of  ashes  ;  and  instead  of  the 
glittering  sand  of  the  sea  and  lake  shore,  a  plain  drab  or  gray,  which  no  wealth 
of  sunshine  or  of  spray  could  turn  to  beauty.  The  slates  used  for  roofing  have 
a  warm  rich  tint ;  oxide  of  iron  puts  vermillion  into  them  as  it  does  into  our 
bricks,  which  else  would  be  only  a  plain  pepper  (and  ealjt.  The  ruddy  hues  of 
brown  now  seen  in  ploughing  sandy  fields,  contracting  sjb  richly  with  the  green 
of  woods  and  meadow,  would  be,  without  the  iron1,  only  the  cold  repulsive  gray 
of  clayey  E  oils.  Mary  marble?,  too,  are  colored  with  this  same  familiar  dye. 
"•  The  violet  veinings  and  variegations  of  the  marbles  of  Sicily  and  Spain,  the 
[flowing  orange  and  amber  of  Sienna,  the  blood-red  color  of  precious  jat'.pcr 
that  enriches  the  temples  of  Italy,"  are  all  painted  with  iron-rust.  Thus  by  an 
infinity  of  design  does  God,  from  the  simplest,  commonest  material,  interweav- 
ing the  beautiful  in  Nature  everywhere,  cultivate  our  taste  and  adorn  the  world 
for  our  happiness. 

$  A  coEchoidal  surface  is  one  that  is  curved  like  the  outside  of  a  watch-crystal.- 


C  O  HP  O  S  I  T  I  O  X  •  0  F     THE 


0  C  K  S  . 


^-Ohio,  Massachusetts,  Arkansas,  Georgia,  etc.  The 
buhrstone  ef  Ohio  contains  some  lime,  and  it  has  been 
thought  that  the  cellular  character  may  be  due  to  the 
partial  dissolving  of  the  lime  out  of  the  stone. 

OEIGIK  OF  QUARTZ.— Though  quartz  is  a  mineral, 
probably  most  of  the  flint  and  hornstone  which  we  find 
is  of  animal  or  vegetable  origin.  Sponges  secrete  little 
spicules  or  points  of  silica.  Diatoms  are  minute  one- 
celled  vegetable  organisms, 
too  small  to  be  seen  singly 
by  the  naked  eye.  Yet  when 
gathered  in  countless  myri- 
ads, they  appear  as  a  brown  or 
reddish  slime.*  They  have 
the  power  of  separating  the 
silex  from  the  water  in  some 
unknown  way.  These  plants 
grow  in  such  numbers  that 
after  their  death  their  inde- 
structible siliceous  coverings 
so  accumulate  as  to  form 
strata  of  great  thickness  and 


Diatoms  from  Albany  and  Waterford, 

extent.    The  hardness,  sharp-  Maine.   • 

B  is  magnified  25  Diameters. 
C  is  magnified  250  Diameters. 
D  is  magnified  200  Diameters. 


ness,  minute  size  and  fragil- 
ity of  the  particles,  whereby 


*  Dr.  Hooker,  in  his  account  of  the  Antarctic  regions,  says :  "  Everywhere  the 
waters  and  the  ice  abounded  in  these  microscopic  vegetables.  They  stained  the 
iceberg  and  pack-ice  wherever  the  latter  was  washed  into  the  sea,  and  imparted 
to  it  a  pale  ocherous  color.  In  the  80th  deg.  of  S.  latitude,  all  the  surface  ice 
carried  along  by  currents,  and  the  sides  of  every  berg,  and  the  base  of  the  great 
Victoria  barrier  itself— a  perpendicular  wall  of  ice  from  one  to  two  hundred  feet 
above  the  sea  level— were  tinged  brown  from  this  cause,  as  if  the  waters  were 
charged  with  oxyd  of  iron."  It  is  a  curious  fact  that  these  minute,  flint-secret- 
ing diatoms  are  th?  food  of  the  soft,  almost  impalpable,  jelly  fish,  and,  as  has 
been  lately  stated,  that  this  in  turn  constitutes  the  food  of  the  huge  whale. 


48  LITHO  LOGICAL       GEOLOGY. 

they  fall  to  pieces  at  the  least  touch,  make  the  mass 
useful  as  a  polishing  material.  Tripoli,  or  polishing 
slate,  is  composed  of  these  siliceous  remains,  a  single 
cubic  inch  containing  41,000,000;  so  that  at  every  stroke 
made  with  the  powder  millions  of  perfect  fossils  are 
crushed  to  atoms.  The  mountain  meal,  or  fossil  farina 
of  Tuscany,  is  a  mass  of  these  organisms.  In  Lapland  a 
similar  earth  is  found,  which  in  times  of  scarcity  the 
inhabitants  mix  with  the  ground  bark  of  trees,  and  use 
for  food.  This  infusorial  earth,  as  it  is  termed,  is 
found  at  various  localities  in  this  country,  as  at  Rich- 
mond, Va.,  Maidstone,  Vt.,  "Waterford,  Me.,  etc.  At 
Bilin,  Bohemia,  besides  a  stratum  of  tripoli  14  feet 
thick,  a  kind  of  semi-opal  occurs,  composed  of  diatoms 
and  sponge  spicules,  cemented  with  siliceous  matter.  It 
is  thought  that  the  more  delicate  shells  were  dissolved 
by  the  water,  and  thus  formed'  opal  cement,  in  which 
the  more  durable  of  the  fossils  are  preserved,  like  insects 
in  amber.  Flint  and  hornstone,  under  the  microscope, 
reveal  the  outlines  of  spicules  of  sponges,  of  diatoms, 
and  of  other  animalcules.  We  are  thence  led  to  believe 
that  perhaps  the  larger  part  of  the  quartz  we  find,  in 
all  its  Protean  forms,  has  impressed  upon  it  an  organic 
structure  which  it  received  at  an  inconceivably  remote 
time,  when  it  was  animated  by  microscopic  life. 

(2.)     ALUMINA. 

&2umina  is  the  oxide  of  the  metal  aluminum,  which, 
on  account  of  its  abundance  in  clay,  is  called  the 
"  clay  metal."  In  hardness,  alumina  is  only  inferior 
to  the  diamond,  and  will  easily  scratch  quartz.  Pure 


COMPOSITION     OF     THIS     11  O  C  K  S .  J^t 

/ 

Su 
crystallized  alumina,  when  bJ»e,  constitutes  the  {(qfqpMifr 

This  ranks  in  value  next  to  the  diamond,  and  some  per- 
fect specimens  have  sold  at  even  a  higher  rate.  The 
dull-colored  variety  is  called  corundum,  and  the  coarse 
granular  kind  emery.  (See  feldspar  and  common  clay, 
page  53.) 

(3.)       LIME. 

/.  Carbonate  of  £ime  is  more  commonly  called 
"  limestone." 

(a.)  LIMESTONE  is  a  compound  of  lime  and  carbonic 
acid.  It  embraces  all  shades  from  white  and  cream  color 
to  a  dense  black.  It  may  be  known  by  its  softness — 
being  easily  scratched  with  a  knife — and  by  its  effer- 
vescing with  an  acid.  Limestone  is  useful  for  building 
purposes,  and  when  the  carbonic  acid  is  expelled  by  heat, 
quick-lime  is  produced. 

(b.)  CALC-SPAR  (Calcite). — Pure  crystals  of  limestone 
are  called  calc-spar.  Those  having  the  fundamental  form 
— the  rhombohedron — 
are  familiarly  termed 
Iceland  spar,  as  they 
were  first  brought  from 
that  country.  They  il- 
lustrate double  refrac- 
tion very  beautifully. 

(c.)  CHALK  is  a  por- 


FIG.  6. 


Object  seen  through  Iceland  Spar. 
Crystal  from  Rossie,  N.  Y. 


ous,  uncompacted  vari- 
ety of  limestone. 

(d.)  CALCAREOUS  TUFA*  is  formed  by  deposition  from 


*  Calcareous  tufa,  or  travertine,  often  forms  beds  of  limestone,  which  can  ba 

3 


50  LITHOLOOICAL      GEOLOGY. 

water  charged  with  carbonate  of  lime  in  solution.  (Rev. 
Chem.,  page  138.)  Stalactites  depend  from  the  roof  of 
caverns  in  limestone  regions.  They  are  produced,  like 
tufa,  from  calcareous  waters.  The  water,  dripping  down 
from  crevices  in  the  rock,  evaporates,  deposits  its  lime- 
stone, and  thus  forms  pendants  of  curious  and  grotesque 
figures.  Some  hang  like  icicles,  while  others  look  like 
falling  sheets  of  water  caught  in  mid-air,  and  turned 
to  stone.  The  drippings  upon  the  floor  produce  calcare- 
ous mounds,  called  stalagmites.  The  two,  meeting,  often 
form  pillars  strangely  grouped  and  interwoven  like  trees 
in  a  forest,  and  sometimes  even  combined  into  broad 
curtains  of  semi-transparent  rock. 

(e.)  OOLITE  (oon,  an  egg,  and 
FIG.  7.  litlws,  a  stone)  is  a  limestone 

consisting  of  numerous  small, 
rounded  grains,  resembling  the 
roe  of  a  fish. 

(f.)  MAUL  is  a  mixture  of 
clay  and  carbonate  of  lime. 
It  is  loose,  friable,  and  gen- 
erally full  of  small  shells.  It 
is  valuable  as  a  fertilizer. 

OOlitic  Marble.  Chester,  England.  (g-)       MAGNESIA*       LlME- 


nsed  for  architectural  purposes.  The  Coliseum  at  Rome  is  built  of  this  rock. 
In  the  vicinity  of  Rome  a  solid  layer  of  this  stone,  a  foot  in  thickness,  has  been 
formed  in  four  months.  Springs  near  the  Tiber  are  famous  for  their  production 
of  travertine. .  Indeed,  the  term  travertine  means  simply  Tiber  stone.  The  water 
of  the  river  near  them  is  eo  charged  with  mineral  matter  that  it  is  said  that 
even  fish  have  been  entangled  and  petrified.  In  certain  regions,  springs  deposit 
the  tufa  so  readily  that  incrustations  may  be  obtained  upon  sticks,  leaves, 
baskets,  etc.  At  the-baths  of  San  Filipo,  Tuscany,  the  preparation  of  casts  in 
this  way  forms  a  regular  business.  Moss  petrified  in  this  manner  is  so  plenti- 
ful in  Caledonia,  N.  Y.,  that  it  is  used  for  building  fences.  It  is  also  found  in 
abundance  at  Chittenango  and  Sharon  Springs. 


COMPOSITION     OF     THE     ROCKS.  51 

BTONE,  or  dolomite,  contains  magnesia.  It  is  harder 
than  limestone,  and  does  not  readily  effervesce  with  an 
acid  unless  heat  is  applied. 

(h.)  MARBLE  is  crystallized  limestone.  When  pure, 
it  is  clear  and  fine-grained,  like  loaf-sugar.  It  is  of 
great  value  in  the  arts.*  The  finest  statuary  marble 
comes  from  Carrara  and  the  island  of  Paros,  whence 
the  term,  Parian  marble,  so  famous  among  the  Greek 
sculptors.  The  pure  whiteness  of  Parian  marble  was 
thought  to  be  especially  pleasing  to  the  gods,  hence  it 
was  selected  for  the  work  of  Praxiteles  and  other  cele- 
brated artists.  The  Venus  de  Medici,  the  Oxford  mar- 
bles, and  many  noted  statues  are  wrought  from  this 
stone.  An  excellent  building  marble  is  quarried  at 
Eutland,  Vt,  in  Massachusetts,  and  in  Connecticut. 
Marble  often  contains  mica  and  other  impurities,  which 
give  it  a  clouded  and  mottled  appearance.  This  de- 
tracts from  its  value,  and  ruins  it  for  statuary  purposes. 
Verde  Antique  is  a  variety  of  marble  streaked  with  ser- 
pentine. 

r' Marble  is  sawed  into  slabs  by  means  of  a  thin  iron 
plate,  a  saw  without  teeth,  driven  by  machinery.  The 
friction  is  produced  by  sharp  sand  and  water,  which  are 


*  What  are  marbles  made  for  ?  Over  the  greater  part  of  the  surface  of  the 
earth  we  find  that  a  rock  has  been  providentially  distributed  in  a  manner 
particularly  pointing  it  out  as  intended  for  the  service  of  man.  It  is  exactly 
of  the  consistence  which  is  best  adapted  for  sculpture  and  architecture.  It  is 
neither  hard  nor  brittle,  nor  flaky,  nor  splintery,  but  uniform  and  delicately, 
yet  not  ignobly  soft— exactly  soft  enough  to  allow  the  sculptor  to  work  it 
without  force,  and  trace  on  it  the  finest  lines  of  finished  form  ;  yet  it  is  so  hard 
as  never  to  betray  the  touch  or  moulder  away  beneath  the  steel ;  and  so  admi- 
rably crystallized  and  of  such  permanent  elements,  that  no  rains  dissolve  it,  no 
lime  changes  it,  no  atmosphere  decomposes  it;  once  shaped,  it  is  shaped  for- 
ever, unless  subjected  to  actual  violence  or  attrition.  This  rock,  then,  is  pre- 
pared by  Nature  for  the  sculptor  and  architect,  as  paper  is  by  the  manufacturer 
for  the  artist ;  nay,  with  greater  care  and  more  perfect  adaptation.- Buskin. 


52  LITHOLOGICAL       GEOLOGY. 

constantly  applied.    The  saws  penetrate  very  slowly,  not 
more  than  an  inch  per  hour. 

ORIGIN  or  LIMESTONE. — Limestone  forms  a  promi- 
nent constituent  of  shells,  bones,  corals,  etc.  Animals 
have  the  power  of  secreting  the  lime  from  the  water  in 
which  they  live,  or  from  the  food  they  eat.  When  they 
die  their  mineral  remains  accumulate  in  great  quanti- 
ties, and  gradually  harden  into  rock.  Chalk  was  formed 
by  the  consolidation  of  minute  shells,  smaller  than  a 
grain  of  sand.  As  each  particle  is  thus  cellular,  and 
not  soli'd,  the  chalk  has  a  soft  porous  structure.  The 
microscope  reveals  these  tiny  shells  in  the  glazing  on  a 
visiting-card.  Even  when  the  rock  contains  no  trace 
of  fossils,  it  may  have  been  made  by  the  sea  breaking 
and  grinding  shells  and  corals  into  a  fine  powder,  just  as 
it  grinds  rock  and  pebbles  into  fine  sand.  We  see  this 
process  now  going  on  in  the  formation  of  coral-reefs,  as, 
for  example,  off  the  coast  of  Florida.  From  the  vast 
extent  of  the  limestone  rock  on  the  earth,  we  can  form 
some  estimate  of  the  amount  of  animal  life  which  has 
existed  in  past  ages. 

2.  Sulphate  of  Zsime,  or,  as  it  is  generally  called, 
'•'  gypsum,"  is  a  compound  of  lime  and  sulphuric  acid. 

GYPSUM  is  readily  distinguished  from  limestone  by  its 
superior  softness.  It  may  be  scratched  with  the  finger- 
nail, and  carved  with  a  knife  into  any  desired  shape.  It 
does  not  effervesce  with  the  acids. 

(a.)  FKCRYSTALLINE  GYPSUM  is  commonly  known  as 
"  plaster  stone."  When  the  stone  is  crushed  and  ground 
it  forms  a  white  powder  sold  as  plaster,  and  used  as  a 
fertilizer. 


COMPOSITION     OF     THE     ROCKS.  53 

(b.)  CRYSTALLINE  GYPSUM  occurs  in  fibrous  masses 
with  a  pearly  lustre,  known  as  satin  spar  ;  in  scales, 
layers,  and  crystals,  pellucid  as  glass,  selenite ;  and  as  a 
snowy- white  solid,  alabaster. 

At  Grand  Rapids,  Mich.,  a  mottled  variety  is  found, 
which  is  turned  in  a  lathe  into  beautiful  vases,  goblets, 
and  other  ornamental  objects.  In  the  mammoth  cave, 
Kentucky,  are  found  exquisite  forms  resembling  leaves, 
flowers,  and  vines.  When  burned,  gypsum  is  known  as 
"  plaster  of  Paris." 

(4.)    TH  E     SILICATES. 

The  Silicates  are  compounds  of  silica  with  other 
substances,  such  as  alumina,  lime,  magnesia,  potash, 
oxide  of  iron,  etc.  The  following  are  the  most  com- 
mon ones : 

/.  feldspar.  This  is  somewhat  softer  than  quartz, 
and,  unlike  it,  has  a  regular  cleavage  on  two  sides,  each 
crystal  showing  a  flat  surface  and  pearly  lustre.  It  has 
usually  a  white  or  flesh-red  color.  There  are  three  vari- 
eties which  are  silicates  of  alumina  with  an  additional 
substance,  viz  :  orthoclase  or  potash-feldspar,  albite  or 
soda-feldspar,  and  labradorite  or  lime-feldspar.  Albite 
(albus,  white)  may  always  be  distinguished  by  its  marked 
whiteness.  Labradorite  (originally  from  Labrador)  ex- 
hibits often  a  beautiful  play  of  colors  from  internal 
reflection,  and  is  susceptible  of  polish.  Clinkstone,  so 
named  because  of  the  metallic  ring  it  emits  when  struck 
with  a  hammer,  is  a  compact  variety  of  feldspar. 

COMMON  CLAY  is  formed  by  the  decomposition  of  feld- 


54  LIT  HO  LOGICAL       GEOLOGY. 

spar  rocks  mixed  with  a  large  proportion  of  quartz  sand. 
Pure  feldspar,  when  decomposed,  produces  kaolin  (high 
ridge,  the  name  of  a  hill  near  Jauchu  Fu,  where  it  is 
obtained),  a  kind  of  clay  used  for  making  porcelain  or 
China-ware.  The  red  color  of  bricks  is  due  to  the  iron 
contained  in  the  clay.  Pipe-clay  is  free  from  iron.  The 
beautiful  pipe-stone  used  by  the  Indians  was  a  compacted 
red  clay  from  Coteau  des  Prairies.  A  bed  of  similar  clay 
is  now  accumulating  in  Lake  Superior. 

2.  Jlficct  (micare,  to  glisten)  is  commonly  called 
"  isinglass."  It  is  easily  known  by  its  lustre  and  by  its 
separating  readily  into  thin  elastic  plates,  which  may 
again  be  subdivided  until  many  thousand  would  be  re- 
quired to  make  an  inch  in  thickness.  It  is  often  seen  in 
sand  as  bright,  glittering  particles.  On  account  of  its 
transparency  it  is  used  in  Siberia  for  windows.  It  is 
employed  on  board  of  ships  where  the  concussion  would 
be  liable  to  break  glass,  and  for  windows  in  stoves.  At 
several  places  in  New  Hampshire,  perfectly  transparent 
plates,  two  or  three  feet  in  diameter,  have  been  obtained. 

3 '.  Hornblende  is  so  named  from  its  toughness. 
It  has  generally  a  black  or  greenish-black  color  and 
a  pearly  lustre.  Some  varieties  present  long,  slender, 
needle-shaped  crystals  of  a  delicate  green  tint  and  a 
glassy  lustre.  Asbestos  (unconsumed)  is  so  fibrous  that 
it  can  be  spun  and  woven  like  cotton.  The  ancients 
made  it  into  napkins,  which,  when  soiled,  were  cleansed 
by  being  thrown  into  the  fire,  where  they  were  burned 
clean  and  white  in  a  few  minutes.  The  Greenlanders 
use  it  for  lampwicks,  and  it  formerly  served  a  similar 


COMPOSITION     OF     THE     ROCKS.  56 

purpose  in  keeping  the  perpetual  fire  in  the  temples, 
its  incombustibility  being  thought  to  render  it  sacred. 
It  is  said  that  in  Siberia 
and  Spain,  gloves,  purses, 
etc.,  are  made  from  ami- 
antlius  (undefilcd),  a  vari- 
ety of  asbestos  having  a 
beautiful  satin  lustre.  The 
finest  locality  for  asbestos 
in  this  country  is  at  the 
Quarantine,  New  York. 

PYROXENE,     Often      Called  Hornblende  Crystals  in  Quartz. 

augite   (from  auge,  lustre), 

is  a  dark-green  mineral,  very  like  hornblende,  and  some 
of  its  massive  specimens  can  hardly  be  distinguished 
from  it.  Its  crystals,  however,  are  stouter  and  thicker, 
and  are  never  needle-shaped,  though  it  has  a  fibrous 
asbestos  which  can  hardly  be  distinguished  from  horn- 
blende except  by  analysis.  Augite  is  a  characteristic 
constituent  of  igneous  rocks. 

£.  2*a2c  is  so  soft  that  it  can  be  cut  with  a  knife, 
and  even  scratched  by  the  finger-nail.  It  separates 
readily  into  thin  pearly  layers,  which  are  not  elastic 
and  tough  like  those  of  mica.  It  has  usually  a  light- 
green  color,  and  an  unctuous  feel  from  the  magnesia  it 
contains.  A  compact  variety  of  talc  is  familiarly  known 
as  «  French  chalk." 

SOAPSTO:N"E  or  steatite  (stear,  fat)  is  a  massive  crys- 
talline variety  which  is  susceptible  of  being  worked  into 
any  desired  form,  and  of  receiving  a  high  polish.  It  can 
be  sawed  into  slabs  or  turned  in  a  lathe.  It  is  made  into 


56 


LITHOLOGICAL       GEOLOGY. 


inkstands,  water-pipes,  and  fire-stones  for  furnaces  and 
culinary  vessels. 

SEKPE^TIXE  is  a  sort  of  compact  talc.  It  differs  from 
steatite  in  being  less  granular  and  more  compact  in  its 
texture,  and  in  being  sometimes  separable  into  layers ; 
it  has  also  a  dull,  resinous  lustre.  It  was  named  from  its 
mottled  colors,  resembling  the  skin  of  a  serpent.  Stoves 
have  been  made  of  it,  as  it  bears  heat  well.  When  pol- 
ished, "precious  serpentine"  has  a  rich,  oil-green  tint, 
and  is  highly  valued  for  inlaid  work. 

OHLOKITE  is  a  mineral  somewhat  resembling  talc  and 
serpentine.  It  has,  however,  a  dark,  olive-green  color,  a 
granular  texture,  and  is  much  less  unctuous  to  the  touch. 
It  forms  a  slaty  rock  very  common  in  some  localities. 

5.    Garnet  is  a  common  mineral  in  connection  with 


FIG.  9. 


Garnets  in    Mica    Schist. 

FIG.  10. 


Tourmaline  Crystals  in  Quartz, 
Alexandria  Bay,  N.  Y. 


miea,  hornblende,  and  gran- 
ite. It  is  found  usually  in 
dark-red  crystals  of  12  or 
24  sides.  This  dodecahe- 
dral  form,  and  its  fracture 
presenting  an  entire  want 
of  cleavage,  with  its  glassy 
lustre,  sufficiently  distin- 
guish it.  The  garnet  is  the 
ancient  carbuncle.  When 
clear-colored  it  is  a  beauti- 
ful gem. 

6.    Tourmaline  is 

found  in  long  prisms  of  3, 
6,  9,  or  12  sides,  each  of 


CLASSIFICATION     OF     THE    ROCKS.        57 

which  is  generally  deeply  furrowed  lengthwise.  It  is  of 
various  colors — black,  red,  green,  and  even  white.  The 
black  crystals  are  highly  polished,  have  no  cleavage,  and 
break  like  resin.  They  are  often  found  as  small  as  a 
knitting-needle,  and  several  inches  long,  radiating  in 
every  direction  through  the  rock  which  contains  them. 


II.     CLASSIFICATION    OF    THE    i§OCKS. 

In  the  earth's  crust  we  find  two  kinds  of  rocks,  pro- 
duced respectively  by  the  action  of  fire  and  of  water. 
The  former  was  poured  out  from  the  furnace  within 
the  earth,  and  the  latter  spread  out  by  the  waters  above. 
These  two  agents,  fire  and  water,  seem  to  have  worked 
jointly  in  laying  the  solid  foundations.  Rocks  are  di- 
vided into  three  different  classes  according  to  their  mode 
of  formation  :  Sedimentary,  igneous,  and  metamorphic. 


(i.)    SEDIMENTARY    ROCKS. 

Sedimentary  ffiocfcs  are  those  which  have  been 
deposited  by  water.  They  are  arranged  in  strata  or 
layers,  and  are  hence  sometimes  called  the  stratified 
rocks.  They  comprise  the  following  kinds: 

/.  Sandstone,  which  is  only  consolidated  sand,  and 
may  be  either  siliceous  or  argillaceous  (clayey). 

2 .  Conglomerate,  which  is  only  consolidated  gravel 
—the  conglomerate  taking  the  name  siliceous,  calcare- 


58  LITHOLOOICAL      GEOLOGY. 

ous,  or  ferruginous  (ferrum,  iron),  from  the  character 
of  the  sandy  paste  which  cements  together  its  pebbles. 
If  the  conglomerate  is  composed  of  rounded  pebbles,  it 
is  often  styled  a  "  pudding  stone ; "  if  of  angular  frag- 
ments, a  "  breccia "  (brek-cea).  The  Potomac  marble, 
seen  in  the  capitol  at  Washington,  is  a  very  beautiful 
calcareous  breccia. 

3 '.  Shale.,  or-  argillaceous  rock,  which  is  composed 
mainly  of  clay,  and  separates  easily  into  thin,  fragile, 
irregular  plates. 

4.  Jjimestone,  which  has  been  pulverized  from 
shells,  corals,  etc.,  by  the  action  of  the  water,  and  been 
deposited  in  sediment  at  the  bottom  of  the  sea. 

SCENIC  DESCRIPTION.-Sandy  regions,  from 
the  shifting  character  of  the  material,  must  be  some- 
times abruptly  uneven  and  irregular,  and  may,  there- 
fore, occasionally  afford  a  pleasing  diversity ;  the  tend- 
ency, however,  is  to  a  flat  and  monotonous  surface, 
Shaly,  and  especially  slaty  formations,  consisting  usu- 
ally of  harder  and  softer  layers,  which  weather  unevenly, 
present  oftentimes  wild  ravines  and  picturesque  water- 
falls, as  in  the  Walking  Glen,  near  Seneca  Lake,  N.  Y. 
The  streams  cut  deep  channels  and  make  abrupt 
plunges  with  unaccountable  leaps,  while  the  tops  of  the 
hills  form  escarpments  with  sharp  edges.  When  the 
clay  shale  is  more  uniform,  it  presents  a  scenery  less 
picturesque,  but  not  less  beautiful.  Gracefully  contoured 
hills  and  grass-carpeted  meadows  in  wide-spreading 
valleys  mark  the  softer  aspects  of  the  rural  landscape^ 


CLASSIFICATION    OF    THE    ROCKS.  59 


(2.)    IGNEOUS    ROCKS. 

Igneotis  flocks  are  those  which  have  been  thrown 
out  in  a  melted  state.  They  are  usually  not  arranged  in 
layers,  and  are  hence  termed  the  unstratified  rocks. 
They  are  divided  into  two  classes — trap  and  volcanic 
rocks. 

/.  2'rap  flocks  are  so  called  from  the  Swedish 
word  trappa,  a  stair,  because  they  frequently  occur  in 
terrace-like  bluffs,  in  the  form  of  massive  steps.  They 
are  generally  black  or  of  a  dark  color,  often  with  shades 
of  green  or  brown.  Their  hardness  renders  them  very  ser- 
viceable in  paving  and  "  macadamizing"  roads,  for  which 
purpose  they  are  largely  used.  Their  dull  and  unattrac- 
tive hues,  and  the  difficulty  of  dressing  them  into  shape, 
unlit  them  for  general  purposes.  They  are,  however, 
very  appropriate  for  Gothic  edifices  on  account  of  the 
appearance  of  age  which  they  give.  There  are  four 
common  varieties  of  the  trap-rock. 

(a.)  BASALT  is  also  called  dolerite  (doleiros,  deceptive), 
because  of  the  difficulty  in  distinguishing  its  constituent 
minerals.  These  are  principally  augite  and  feldspar.  It 
sometimes  contains,  scattered  through  it,  crystals  of  a 
bottle-glass  green  color,  called  chrysolite  (olivine).  When 
the  rock  weathers,  these  little  grains  fall  out.  They  are 
found  of  considerable  size  at  Isle  Royale,  Lake  Superior. 
They  are  used  as  gems,  though  they  are  quite  soft  and 
have  little  lustre. 

(b.)  GREENSTONE — known  sometimes  as  "ironstone"- 


60 


LITHOLOGICAL      GEOLOGY. 


FIG.  ii. 


is  also  called  diorite  (dioros,  distinct),  because  its  com- 
position is  so  readily  determined.  It  consists  of  horn- 
blende and  feldspar.  Most  of  the  trap -rocks  of  the 
Eastern  States  are  diorite. 

(c.)  PORPHYRY  (porplmra,  purple)  is  so  named  from 
a  purple  variety  which  was  highly  prized  in  Egypt.     It 

consisted  of  a  red  feldspar 
with  rose-colored  crystals 
scattered  through  it.  It 
was  susceptible  of  a  high 
polish,  and  was  very  en- 
during, hence  it  was  much 
sought  after  by  the  an- 
cients, who  wrought  it 
into  sepulchres,  baths, 
obelisks,  etc.  Any  trap- 
rock  in  which  the  feld- 
spar is  disseminated  in 
distinct  crystals  is  said 
to  be  porphyritic. 

(d.)  AMYGDALOID 
(amygdala,  an  almond)  is 
a  name  applied  to  certain 
trap-rocks  which  contain 
rounded  cavities  often 
filled  with  quartz,  calcite, 
etc.,  so  that  the  rock  ap- 
pears like  a  cake  stuck 
full  of  almonds. 


Lava  (Scoria),  in  part  turned  into  an 
Amygdaloid. 


SCENIC    DESCRIPTION. -The    most    striking 
characteristic  of  the  trap-rocks  is  their  columnar  struc- 


CLASSIFICATION     OF     THE     ROCKS.         61 

ture.*  They  are  crystallized  into  prisms  more  or  less 
regular,  with  from  three  to  eight  sides,  a  diameter  of 
from  one  inch  to  many  feet,  and  a  height  often  of  sev- 
eral hundred  feet.  These  pillars  are  frequently  jointed, 
and  the  sections  are  concave  at  the  top  and  convex  at  the 
bottom.  The  columns  often  stand  perpendicularly,  and 
when  broken  and  disintegrated  by  the  action  of  the 
weather  or  of  the  sea,  present  most  picturesque  appear- 
ances as  of  old  castles  and  of  ruined  fortifications.  Some 
of  the  most  remarkable  scenery  in  the  world  is  of  this 
character.  FingaFs  Cave,  Isle  of  Staffa,  and  the  Giant's 

FIG.  13. 


Fingal's  Cave.    (From  a  Photograph.) 


*  We  suppose  that  the  columnar  structure  of  trap-rocks  has  resulted  from  a 
port  of  crystallization  while  cooling  under  pressure  from  a  melted  state,  for  two 
reasons :  1,  similar  columns  are  found  in  recent  lavas ;  and,  2,  from  experiment, 
Mr.  Watt  melted  700  Ibs.  of  basalt,  and  caused  it  to  cool  slowly,  when  globular 
masses  were  formed,  which  enlarged  and  pressed  against  one  another  until  reg- 
ular columns  were  the  result. 

This  can  be  illustrated  by  putting  balls  of  putty  into  a  vessel,  and  gently  pressing 


62  LITHOLOOICAL      GEOLOGY. 

Causeway*  in  the  north  of  Ireland,  are  familiar  exam- 
ples. On  the  north  shore  of  Lake  Superior,  among  the 
Palisades  on  the  Hudson,  upon  Mts.  Tom  and  Holyoke, 
Mass.,  along  the  banks  of  the  Columbia  Biver,  and  the 
Penobscot  in  Maine,  are  presented  many  similar  scenes. 
Trap-rocks,  when  weathered,  acquire  a  dull,  dark  brown 
appearance,  and  are  often  colored  with  patches  of  white 
lichens.  There  are  cases  of  the  existence  of  basalt  in 
well-defined  flows,  which  still  adhere  to  craters  visible  at 
the  present  day,  and  in  regard  to  the  igneous  origin  of 
which  there  can  be  no  doubt.  One  of  the  most  striking 
examples  of  a  basaltic  crater  is  that  of  La  Coupe  in  the 
south  of  France.  Upon  the  flank  of  this  mountain,  the 
traces  left  by  the  current  of  liquefied  basalt  are  still  seen 
occupying  the  bottom  of  a  narrow  valley,  except  at  those 
places  where  the  river  Volant  has  cut  away  portions  of 
the  lava.  Trappean  regions  abound  in "  perpendicular 
walls,  sharp  ascents,  and  abrupt  precipices.  The  erup- 
tive masses  often  rise  from  amid  level  plains,  while  hard 
iikes .  alternate  with  rich  strata  which  decompose  *  into 


upon  them,  when  they  will  be  seen  to  arrange  themselves  in  five  and  six-sided 
columns,  precisely  similar  to  the  five  and  six-sided  columns  of  Stafla  or  the 
Giant's  Causeway.— Page. 

*  Hogg,  the  "  Ettrick  Shepherd,11  thus  graphically  refers  to  these  grandeurs 
of  Nature : 

"Awed  to  deep  silence,  they  tread  the  strand 

Where  furnaced  pillars  in  order  stand  ; 

All  framed  of  the  liquid  burning  levin, 

And  bent  like  the  bow  that  spans  the  heaven  ; 

Or  upright  ranged,  in  wondrous  array 

With  purple  of  green  o'er  the  darksome  gray. 

The  solemn  rows  in  that  ocean  den 

Were  dimly  seen  like  the  forms  of  men ; 

Like  giant  monks  in  ages  agone, 

Whom  the  god  of  the  ocean  had  seared  to  stone  ; 

And  their  path  was  on  wondrous  pavement  old 

In  blocks  all  cast  in  some  giant  mould.11 


f.  "* 


CLASSIFICATION     OF     THE     ROCKS.        65 

fertile  soils.  The  soft  plain  ascends  often  at  one  stride 
into  a  hill  fantastically  rugged ;  and  bare,  fractured 
precipices  overtop  level  fields  and  terraced  slopes  rich  in 
verdure.* 

2 .   Yolcanic  ffiocfcs  are  of  two  common  varieties. 

(a.)  TEACH YTE  (trachus,  rough)  is  so  named  because 
of  its  rough,  gritty  feel.  It  is  porous,  has  a  white,  gray, 
or  'black  color,  and  is  usually  porphyritic.  It  is  abundant 
in  South  America — the  colossal  Chimborazo  being  a  lofty 
trachytic  cone — -in  the  extinct  volcanic  regions  of  the 
west,  on  the  banks  of  the  Rhine,  and  in  France. 

(b.)  LAVA  is  a  term  applied  to  all  melted  matter 
observed  to  flow  in  streams  from  volcanoes.  It  consists 
'  almost  entirely  of  augite  (pyroxene)  and  feldspar.f  The 
former  constitutes  dark  colored,  and  the  latter  light  col- 
ored lava.  When  cooled,  the  upper  part  of  the  stream 
is  light  and  porous  as  a  sponge,  from  the  expansion  of 


*  Hugh  Miller  has  mentioned  the  curious  fact  that  all,  or  nearly  all,  the  noted 
Scottish  fortresses  are  built  upon  trappean  rocks.  Thus  the  early  geologic 
history  of  a  country  seems  typical  of  its  subsequent  civil  history.  A  stormy 
morning,  during  which  its  strata  have  been  tilted  into  abrupt  angles  and  yawn- 
ing chasms,  is  generally  succeeded  by  a  stormy  day  of  fierce  wars,  protracted 
sieges,  and  all  the  turmoil  of  human  passion.  Amid  the  centers  of  disturbance, 
the  natural  strongholds  of  the  earth,  the  true  battles  of  the  race  have  been 
fought.  Greece,  the  Holy-  Land,  the  Swiss  Cantons,  Scotland,  New  England, 
all  have  been  grand  theatres  alike  of  geologic  and  of  patriotic  strife. 

t  Other  simple  minerals  occur  in  lava.  At  least  100  species  have  been  de- 
tected in  that  of  Vesuvius,  but  they  bear  eo  small  a  proportion  to  the  wholf 
mass  as  to  render  it  incompatible  with  the  design  of  this  work  to  devote  spac< 
to  them  here.  There  are  al  ?o  thrown  out  from  volcanoes  "  fragments  of  grair 
ite  and  other  rocks  scarcely  altered ;  cinders  and  ashes  of  various  decrees  o1 
fineness,  which  are  sometimes  converted  into  mud  by  the  water  that  accom- 
panies them  ;  also  sulphur  in  a  pure  state ;  various  salts  and  acids  ;  and  several 
gases,  among  which  are  the  hydrochloric,  sulphurous,  and  sulphuric  acids ; 
alum,  gypsum,  sulphates  of  iron  and  magnesia,  chlorides  of  sodium  and  potas- 
sium, of  iron,  copper,  and  cobalt ;  chlorine,  nitrogen,  sulphuretted  hydrogen." 
etc.  —Hitchcock. 


66 


LITHOLOOICAL      GEOLOGY. 


the  steam  bubbles,  and  will  swim  in  water,  while  the  lower 
portions  are  hard  and  compact  like  the  ancient  basalt. 
The  porous  lava  is  called  scoria.  Pumice  is  a  feldspathic 
scoria  with  long,  slender  air-cavities,  drawn  out  by  the 
forward  movement  of  the  lava  stream ;  large  quantities 
of  it  are  often  found  floating  in  the  ocean.  It  is  much 
used  in  polishing  marble.  Obsidian  is  a  glassy-like  lava. 

SCENIC  DESCRIPTION*-Regions  of  frequent 
volcanic  action  contain  cones  and  craters  surrounded  by 
beds  of  lava  and  scoria.  These  features  are  well  exhibited 
in  the  accompanying  view  of  a  scene  near  Mono  Lake, 
Sierra  Nevada  region. 

FIG.  15. 


Volcanic  Cones,  near  Mono  Lake. 


(3.)     M  ETAMORPH  1C     ROCKS. 

JlfelamorpMc  ffiocfcs  are  those  which  have  been 
altered  by  heat.      A  mass  of  melted  lava  penetrating 


CLASSIFICATION     OF     THE     ROCKS.         67 

sedimentary  rocks  would  materially  modify  their  char- 
acter ;  the  clay  would  be  changed  to  slate,  the  limestone 
converted  into  marble,  earthy  sandstone  and  clay  rocks 
into  granite-like  rocks,  and  the  impurities  crystallized 
into  various  minerals.*  The  stratification  would  be  de- 
stroyed, and  the  fossils  in  part,  if  not  entirely,  obliter- 
ated. Sometimes,  however,  the  original  fossils  may  be 
still  distinguished.  There  is  a  kind  of  marble  found  at 
Kilkenny  which  contains  shells  of  the  ammonite.  They 
look  exactly  like  the  prints  of  a  careless  heel,  and  many  a 
housekeeper  has  wearied  herself  in  vainly  trying  to  scour 
out  these  fossil  remains.  The  famous  Carrara  marble  is  a 
metamorphic  limestone.  On  examination  with  a  lens  it 
reveals  spangles  of  graphite,  and  frequently  nodules  of 
ironstone  lined  with  perfectly  limpid  crystals  of  quartz. 
These  accidental  defects,  resulting  from  impurities  in  the 
limestone,  are  very  annoying  to  the  sculptor,  since  noth- 
ing in  the  exterior  of  a  block  betrays  their  existence. 

/.  Granite  (from  the  Italian  grano,  because  of  its 
granular  structure)  consists  of  feldspar,  mica,  and  quartz. 
The  feldspar  shows  a  smooth  surface  of  cleavage  in  two 
directions,  and  is  usually  of  a  white  or  flesh  color ;  the 
mica  may  be  readily  recognized  by  its  glistening  look, 


*  In  Whitney's  Geological  Survey  of  California,  constant  illustrations  are 
given  of  the  effects  of  metamorphism.  Places  were  found  where  the  line  of 
separation  between  the  sedimentary  and  metamorphic  rocks  is  sharply  drawn. 
Near  the  junction  of  the  two  kinds,  the  latter  seem  to  have  Detained  their  origi- 
nal stratification.  Patches  of  sedimentary  rocks  which  entirely  escaped  the 
igneous  action  are  inclosed  in  the  metamorphic  rocks.  Here  is  a  layer  of 
quartz,  which  beyond  is  converted  into  jasper ;  a  clayey  sandstone  into  sei  - 
pentine,  or  into  mica  slate  with  disseminated  garnets.  The  metamorphic  and 
sedimentary  rocks  give  each  a  distinctive  character  to  the  landscape.  The 
former  furnish  hills  of  sharper  outline,  richer  soil,  and  more  abundant  vegeta- 
tion, so  as  to  be  readily  recognized  even  at  a  distance. 


68  LITHOLOGICAL      GEOLOGY. 

and  by  being  easily  separated  into  thin  layers ;  the 
quartz  has  a  -glassy  lustre  and  no  cleavage.  Graphic 
granite  is  a  variety  in  which  the  quartz  is  imperfectly 
crystallized  into  long,  slender  crystals.  When  the  rock 
is  broken  crosswise,  the 
ends  of  these  crystals  pre-  FlG-  l6- 

sent  forms  somewhat  re- 
sembling Hebrew  charac- 
ters. Sometimes  granite 
has  a  very  coarse  struc- 
ture, the  crystals  being  a 
foot  or  more  in  diameter ; 
at  other  times  it  is  so  fine 

that     One     Can    With     diffi-  Graphic  Granite,  Berkshire,  Mass. 

culty  distinguish  the  con- 
stituent minerals.  When  sound,  it  is  an  excellent  build- 
ing stone,  but  does  not  merit  the  character  of  extreme 
hardness  which  is  proverbially  ascribed  to  it.  Its  granu- 
lar texture  unfits  it  for  road-making,  since  it  is  crushed 
into  dust  so  readily  by  tramping  feet.  In  the  Crimean 
war  it  was  shown  that  granite  ramparts  were  as  easily  de- 
molished as  those  of  limestone.  Granite  seems  to  be  the 
lowest  rock  in  the  earth's  formation,  and  yet,  strangely 
enough,  it  is  found  on  Mt.  Blanc — the  highest  in  Europe, 
and  crowns  many  of  the  Eocky  Mountains. 

Granite  is  quarried  in  great  quantities  in  the  East- 
ern States  for  building  purposes.  New  Hampshire  and 
Massachusetts  are  noted  for  their  extensive  beds.  They 
may  be  called  the  Granite  States  of  the  Union.  The 
granite  is  detached  in  blocks  by  drilling  a  series  of 
holes,  one  every  few  inches,  to  a  depth  of  three  inches, 
and  then  driving  in  wedges  of  iron  between  steel  cheeks. 


CLASSIFICATION     OF     THE     ROCKS  69 

In  this  manner,  masses  of  any  size  are  split  out.  There 
is  a  choice  of  direction,  as  the  granite  has  certain  direc- 
tions of  easiest  fracture.  Masses  120  feet  in  length  have 
been  obtained  at  some  of  the  quarries.  Granite  was 
highly  prized  by  the  ancients.  There  are  granite  obel- 
isks in  Egypt  which  have  stood  for  3,000  years.  Pom- 
pey's  Pillar  and  several  of  the  principal  Pyramids  are 
composed  of  this  material. 

EOSMATIOK  OF  GEANITE. — Granite  is  often  styled  the 
primitive  rock,  since  it  seems  to  be  the  one  which  consti- 
tutes the  basement  of  the  earth's  crust.  Though  it  may 
now  lie  at  the  foundation,  it  may  still  be  a  metamorphic 
rock,  and  not  the  first  product  of  the  slowly  cooling 
globe.  It  is  more  likely  that  most  of  the  granite  rocks 
have  resulted  from  the  wearing  down  of  the  primeval 
crust  of  true  igneous  rocks.  These  were  carried  into 
the  sea  and  deposited  as  stratified  rock.  Buried  after- 
ward beneath  vast  accumulations  of  other  rocks,  by  the 
internal  heat  and  the  influx  of  hot  water  charged  with 
various  chemical  agents,*  they  were  crystallized,  and 
their  fossils  and  stratification  obliterated.  Again,  they 
may  have  been  worn  by  the  sea,  deposited,  and  afterward 

*  In  the  account  given  of  the  Pluton  Geysers,  California,  we  seem  to  have  an 
insight  into  the  laboratory  of  the  world,  and  can  learn  something  of  the  chemi- 
cal changes  which  have  been  going  on  in  past  ages.  These  geysers  are  hot 
springs,  which  throw  out  intermittingly  and  spasmodically  powerful  jets  of 
steam  and  scalding  water,  fheir  temperature  varying  from  93°  to  169'  F.  The 
water  contains  sulphuric  acid,  sulphuretted  hydrogen,  and  probably  other  active 
solvents.  The  rocks  are  rapidly  dissolving  under  this  powerful  metamorphic 
action.  Porphyry  and  jasper  are  transformed  into  a  kind  of  potter's  clay.  Trap 
and  magnesian  rocks  are  consumed,  much  like  wood  in  a  slow  fire,  forming-  sul- 
phate of  magnesia  and  other  products.  Granite  is  rendered  so  soft  that  one  can 
crush  it  between  his  fingers  as  easily  as  unbaked  bread.  The  feldspar  is  con- 
verted partly  into  alum.  The  boulders  and  angular  fragments  brought  down  the 
ravine  by  floods  are  being  converted  into  a  firm  conglomerate,  so  that  it  is  diffi- 
cult to  dislodge  even  a  small  pebble,  the  pebble  itself  sometimes  breaking  before 
the  cement  will  yield. — Shepherd,  Am.  Jmirn.  of  Scienca. 


70  LI  TH  OLOG 1 C  AL      GEOLOGY. 

metamorphosed.  How  many  times  this  cycle  of  change, 
has  taken  place,  we  have  no  way  of  judging.  The  entire 
crust  of  the  earth  has  doubtless  undergone  metamorphic 
action,  to  some  extent  at  least,  and  is  unlike  what  it  was 
when  created.  What  made  up  that  primeval  crust  we  do 
not  know,  and  hence  cannot  tell  whether  any  of  the 
ancient  formation,  survives.  It  is  generally  believed  that 
granite  could  not  be  produced  directly  by  the  cooling  of 
the  melted  lava  that  then  composed  the  globe.  There 
are,  however,  places  where  it  has  been  found  at  a  great 
depth,  and,  by  some  powerful  convulsion,  has  been  ejected 
to  the  surface  in  a  melted  state,  like  a  true  igneous  rock. 
It  may  even  now  be  in  the  process  of  formation  in  the 
lower  portions  of  the  earth's  crust.  It  is  certain  that  as 
the  crust  wears  away  above,  new  rocks  must  be  cooling 
underneath,  since  the  point  of  fusion  is  constantly  pass- 
ing downward.  Granite  has,  however,  been  formed  in  all 
ages,  of  the  world,  and  cannot  be  thought  a  primitive 
rock  merely,  although  specially  characteristic  of  the 
earlier  periods.  We  shall,  therefore,  consider  it,  in  gen- 
eral, as  a  metamorphic  rock  crystallized  by  the  combined 
action  of  heat,  ivater,  and  other  chemical  agents,  from  sedi- 
mentary or  mftre  ancient  rocks. 

SCENIC  DESCHIPTIOHf.-The  ancient  granite, 
having  been  exposed  for  so  long  a  time  to  the  wear  of 
the  elements,  rarely  imparts  boldness  or  grandeur  to  the 
landscape,  unless  more  recent  convulsions  have  broken  it 
up  and  rendered  it  picturesque.  When  containing  little 
feldspar,  and  being  therefore  more  durable,  it  forms  lofty 
pyramidal  peaks  of  sharp  outline  that  rise  in  enormous 
spires,  as  in  the  vicinity  of  Mt.  Blanc.  There  seems  to 


CLASSIFICATION     OF     THE     ROCKS.         71 

be  often   a  tendency  to  rounded  concentric  outlines,* 
which  render  the  view  sombre  and  uninteresting.     The 

FIG.  17. 


North  Dome— Yosemite  Valley. 

peculiar  dome-like  appearance  of  granite  mountains  is 
beautifully  illustrated  in  the  magnificent  scenery  of  the 

*  Humboldt  says :  "  All  formations  are  common  to  every  quarter  of  the  globe, 
and  assume  the  like  forms.  Everywhere  basalt  rises  in  twin  mountains  and 
truncated  cones  ;  everywhere  trap  porphyry  presents  itself  to  the  eye  under  the 
form  of  grotesquely  shaped  masses  of  rock  ;  while  granite  terminates  in  gently 
rounded  summits."  As  the  pupil  will  observe,  however,  this  latter  is  but  one 
of  the  a?pects  which  granite  presents. 


72  LITHOLOGICAL      GEOLOGY. 

Yosemite.  Its  colossal  peaks  are  of  solid  granite,  the 
North  Dome  being  3568  feet  in  height.  Granite  forms, 
in  general,  lofty  hills  and  elevated  table-lands,  which  are 
rendered  still  more  bleak  and  forbidding  by  the  snow- 
clad  peaks  of  the  more  elevated  mountains.  The  soil  is 
generally  scanty  and  barren.  The  clay  from  the  decom- 
posed granite  is  the  finest  and  best  that  can  be  found ; 
the  sand,  often  of  the  purest  white,  always  lustrous  and 
bright.  As  a  result,  the  landscape  wears  a  peculiar 
aspect  of  purity.*  It  cannot  become  muddy,  foul,  or 
unwholesome.  The  streams  may  indeed  be  opaque  and 
white  as  cream  with  the  churned  substance  of  the  weath- 
ered granite;  but  the  water  is  good  and  pure,  and  the 
shores  not  slimy  nor  treacherous,  but  pebbly  or  of  firm 
and  sparkling  sand.  The  quiet  springs  and  lakes  are  of 
exquisite  clearness,  and  the  sea,  which  washes  a  granite 
coast,  is  as  unsullied  as  a  flawless  emerald. 

2 .  Gneiss  (nice)  differs  from  granite  only  in  being 
stratified.  Indeed,  the  two  kinds  of  rock  pass  into  each 
other  so  insensibly  that  they  are  often  difficult  to  dis- 


*  It  is  remarkable  how  this  intense  purity  in  the  country  seems  to  influence 
the  character  of  the  inhabitants.  It  is  almost  impossible  to  make  a  cottage  built 
in  a  granite  country  look  absolutely  miserable.  Rough  it  may  be,  neglected, 
cold,  full  of  aspect  of  hardship,  but  it  never  can  look  foul ;  no  matter  how  care- 
lessly, how  indolently  its  inhabitants  may  live,  the  water  at  their  doors  will  not 
stagnate,  the  soil  at  their  feet  will  not  allow  itself  to  be  trodden  into  slime  ;  they 
cannot  so  much  as  dirty  their  faces  or  hands  if  they  try.  Do  the  worst  they  can, 
there  will  still  be  a  feeling  of  firm  ground  under  them  and  pure  air  about  them, 
and  an  inherent  wholesomeness  which  it  will  need  the  misery  of  years  to  con- 
quer. The  inhabitants  of  granite  countries  have,  too,  a  force  and  healthiness  of 
character  about  them,  abated  or  modified  according  to  their  other  circumstances 
of  life,  that  clearly  distinguish  them  from  the  inhabitants  of  less  pure  dis- 
tricts.— Euskin. 


CLASSIFICATION     OF     THE     ROCKS.          73 

tinguish.*  Its  origin,  therefore,  is  doubtless  the  same  as 
that  of  granite,  both  being  made  from  stratified  rocks ; 
when  the  stratification  entirely  disappeared,  granite  being 
the  result ;  and  when  only  partially  or  not  at  all,  gneiss. 
Because  of  the  ease  with  which  it  divides  into  thin  layers, 
this  rock  is  much  used  for  flagging. 

SGE1ITIC  DESCRIPTIOH.-In  our  own  country 
we  find  much  of  the  grand  scenery  of  the  White  Moun- 
tains, Blue  Ridge,  and  Rocky  Mountains,  among  rocks 
of  this  formation.  Hugh  Miller,  humorously  speaking 
of  the  gneiss  hills  of  Scotland,  says  :  A  gneiss  hill  is 
usually  massive,  rounded,  broad  of  base,  and  withal 
somewhat  squat,  as  if  it  were  a  mountain  well  begun, 
but  interdicted  somehow  in  the  building,  rather  than  a 
finished  mountain.  It  seems  almost  always  to  lack  the 
upper  stories  and  the  pinnacles.  It  is,  if  I  may  so  ex- 
press myself,  a  hill  of  one  heave ;  whereas  all  our  more 
imposing  Scottish  hills — such  as  Ben  Nevis  and  Ben 
Lomond — are  hills  of  at  least  two  heaves ;  and  hence  in 
journeying  through  a  gneiss  district,  there  is  a  frequent 
feeling  on  the  part  of  the  traveler  that  the  scenery  is 
incomplete,  but  that  a  few  hills,  judiciously  set  down 
upon  the  tops  of  the  other  hills,  would  give  it  the 


*  Doubtless  some  gneiss  has  been  formed  by  the  action  of  water,  and  is  per- 
haps a  sedimentary  rock.  Thus  granite  being  worn  away  by  the  waves,  the 
granite  debris  would  be  deposited  in  regular  strata  at  the  bottom  of  the  sea, 
constituting  gneiss.  Most  of  it  is,  however,  the  product  of  an  incomplete  meta- 
morphic  action,  which,  if  made  complete,  would  have  produced  true  granite  by 
destruction  of  all  fossils  and  stratification.  Thus  Dawson,  in  his  Acadian 
Geology,  says  that  in  Nova  Scotia,  near  the  Nictaux  river,  there  are  beds  of 
elate  in  which  the  granite  has  been  intruded,  and  the  slates  near  the  junction 
have  been  altered  into  gneiss  containing  garnets.  Here  is  a  case  of  clear  meta- 
morphism  of  shale  into  gneiss. 


74  LITHOLOGICAL      GEOLOGY. 

proper  finish.    No  hill,  however,  accomplishes  more  with 
a  single  heave  than  a  gneiss  one. 

3.  Mica  Schist  is  a  gneiss  rock,  consisting  mostly 
of  mica.  The  dust  in  the  roads  of  places  abounding  in 
this  rock  is  full  of  the  fine  glistening  particles  of  mica. 

SCENIC  DESCRIPTION. -The  scenery  of  re- 
gions  where  mica  schist  predominates  is  bold,  rugged, 
and  unfertile.  Thrown  into  lofty  mountains  by  the  pro- 
truding granite,  and  often  tilted  in  nearly  vertical  posi- 
tions, they  present  that  rugged  and  abrupt  aspect  so 
characteristic  of  the  Scottish  highlands  and  some  of 
the  mountain  ranges  of  our  own  country.  Loch  Kat- 
rine and  many  other  places,  classic  for  their  picturesque 
beauty,  owe  their  origin  to  the  peculiarities  of  this  for- 
mation. Hugh  Miller  says :  "  Their  gray  locks  of  silky 
lustre  are  curved,  wrinkled,  contorted,  so  as  to  remind 
us  of  pieces  of  ill-laid-by  satin,  that  bear  on  their  crushed 
surfaces  the  creases  and  crumplings  of  a  thousand  care- 
less foldings."' 

£.  Syenite  is  a  granite  in  which  the  mica  is  re- 
placed by  hornblende.  It  is  so  called  from  the  city 
of  Syene,  Upper  Egypt,  where  the  ancient  Egyptians 
quarried  it  for  monumental  purposes.*  The  celebrated 
Quincy  granite  is  mostly  of  this  class.  It  is  largely  used 
in  architecture,  many  public  edifices  being  composed  of 
it ;  for  example,  the  Bunker  Hill  monument,  the  custom- 


*  It  has  since  been  found,  however,  that  the  ancient  syenite  is  only  a  granite 
with  black  mica,  and  not  hornblende  as  was  supposed.  As  the  upper  part  of 
Mt.  Sinai  is  a  mass  of  true  sj^enite.  it  has  been  proposed  to  rename  this  rock  as 
tinaite, 


CLASSIFICATION     OF     THE     ROCKS.         75 

houses  at  Boston  and  New  Orleans,  and  the  Astor  House 
in  New  York. 

5 '.  Quart zite  is  a  rock  composed  of  quartz  sand 
cemented  by  heat.  In  a  quartz  district,  because  of  the 
slow  weathering,  the  hills  present  a  scenery  of  savage 
wildness,  but  wonderful  grandeur. 

6.  Marble  is  metamorphosed  limestone.  The  dif- 
ferent varieties  have  already  been  described  on  page  51. 
Limestone  is  one  of  the  rocks  in  which  the  metamor- 
phic  action  can  be  most  easily  traced.  When  not  thus 
modified  we  find  it  as  common  limestone,  chalk,  etc. 
By  heat  its  character  is  entirely  changed ;  it  takes  on 
a  crystalline  -structure,  its  color  is  varied,  the  fossils  are 
generally  destroyed,  and  the  various  impurities  form  new 
minerals  which  often  fill  the  veins  of  the  marble  with 
beautiful  colored  figures,  as  seen  in  the  variegated  mar- 
bles of  California. 

There  are  also  other  varieties  of  metamorphic  rocks, 
viz.,  talcose  schist,  a  slate  which  contains  much  talc,  chlo- 
rite schist,  one  which  contains  chlorite  (an  olive-green 
mineral  very  like  talc),  and  slate  rock,  which  passes  almost 
insensibly  into  an  argillaceous  or  clayey  shale. 


III.     STRUCTURE    OF    THE    MOCKS. 

t2>  CJO 

The  rocks  of  the  earth's  crust  are  divided  according 
to  their  structure  into  two  classes,  the  stratified  and  the 
unstratified  rocks.  The  former  are  arranged  in  layers, 
the  latter  are  not  The  former  were  generally  produced 


70  L1THOLOGICAL      GEOLOGY. 

by  aqueous,  the  latter  by  igneous  agencies.  The  former 
mark  the  periods  of  rest  in  the  world's  history,  the  lat- 
ter chronicle  its  convulsions.  Upon  the  exterior  of  the 
crust  the  stratified  rocks  are  largely  in  excess,  occupy- 
ing probably  J§  of  the  surface;  upon  the  interior,  how- 
ever, the  unstratified  comprise  the  whole  mass,  and  ex- 
tend to  a  depth  of  perhaps  50  miles.  Historical  geology 
deals  almost  entirely  with  the  stratified  rocks,  and  nearly 
all  of  its  principles  are  based  upon  facts  which  they  dis- 
close. 

STRATIFIED     ROCKS. 

As  soon  as  dry  land  was  formed,  it  began  to  be  worn 
away  by  the  ceaseless  action  of  the  rain  and  the  restless 
sea,  depositing  the  debris  at  the  bottom  of  the  ocean.* 
Thus,  while  the  earth's  crust  has  been  growing  from 
below  by  the  formation  of  unstratified,  it  has  been  grow- 
ing above  by  the  formation  of  stratified  rocks.  These 
materials  are  arranged  in  comparatively  flat  layers  as  in 
Fig.  18.  In  this  way  the  earth  would  be  covered  over 
by  successive  deposits  like  the  coats  of  an  onion. . 

FIG.  18. 


/.     *Dis2ocations    of  Strata. — Had  these  wrap- 


*  It  is  probable  also  that  submarine  volcanoes  poured  their  liquid  streams 
into  the  primeval  ocean.  These  materials  were  worked  over  and  deposited  as 
stratified  rocks.  The  earliest  strata,  says  Agassiz,  are  pierced  with  numerous 
funnels,  which  were  outlets  for  the  fierce  floods  beneath. 


STRUCTURE     OF     THE     ROCKS. 


77 


pings  remained  undisturbed,  we  could  have  made  little 
progress  in  deciphering  their  history,  since  we  have  not 
pierced  the  crust  much  more  than  half  a  mile  in  perpen- 
dicular line.  But  by  igneous  action,  the  rocks  which 
would  have  lain  as  in  Fig.  18  have  been  upheaved,  and 
present  a  form  similar  to  that  shown  in  Fig.  19,  where 

FIG  19. 


we  can  examine,  on  the  top,  the  edges  of  various  sedi- 
mentary strata,  and  also  the  igneous  rocks  which  were 
hidden  below.  Oftentimes  the  geologist,  in  tracing  the 
course  of  a  river,  will  find  successive  strata  tilted  up  on 
edge,  presenting  the  appearance  represented  in  Fig.  20. 

FIG.  20. 


Here,  had  the  rocks  remained  in  their  original  position, 
the  river  in  its  descent  might  not  have  disclosed  more 
than  two  or  three  layers ;  now,  by  the  outcropping,  as  it 
is  termed,  many  successive  strata  can  be  examined  often- 
times within  a  few  miles. 


78 


LITHOLOGICAL      GEOLOGY. 


2.  ^Definitions . — A  stratum  includes  one  or  more 
layers,  or  lamina^  of  any  particular  kind  of  rock.  A  /or- 
mation  is  composed  of  several  strata  which  were  deposited 
in  the  same  period.  A  group  is  a  part  of  a  formation, 
including  such  strata  as  are  in  any  way  related  to  each 
other.  The  laminae,  or  layers,  of  a  group  bear  the  same 
relation  to  each  other  that  the.  groups  of  a  formation  do. 

In  Fig.  21  the  strata  at  A  are  said  to  be  horizontal, 

FIG.  21. 


those  at  B  inclined  (and  the  angle  which  they  form 
with  the  horizon  is  called  the  dip),  those  at  E  to  be 
tilted  up,  at  C  to  be  vertical,  and  at  D  to  be  contorted. 
In  Fig.  22,  strata  dipping  in  opposite  directions,  a,  are 


FIG.  22. 


called  anticlinal;  when  dipping  toward  each  other,  s, 
synclinal;  e  is  an  escarpment  or  bluff;  strata,  as  c, 
coming  to  the  surface,  are  called  an  outcrop;  strata 
arranged  regularly  above  each  other,  as  at  o,  are  said 


STRUCTURE     OF     THE     ROCKS. 


79 


to  be  conformable;   those  not,  as  at  x,  are   styled  un- 
conformable. 

3.    ^Diverse   Stratification.  —  Sedimentary  rocks 
were  not  always  originally  deposited  in  horizontal  layers. 

FIG.  23. 


Diverse  Stratification. 


Along  the  sea-shore  we  can  see  the  deposits  being  made 
on  its  sloping  bottom.  The  ebb  and  flow  of  the  tide,  the 
sand  blown  by  the  wind,  and  the  action  of  the  waves, 
which  often  undermine  one  part  and  elevate  another, 
may  cause  a  rock  to  present  the  diverse  stratification 
seen  in  Fig.  23. 

-£.  Inanimation. — It  is  necessary  to  distinguish  be- 
tween stratification  and  lamination.  Separate  laminae, 
as  well  as  strata,  indicate  a  pause  in  the  process  of  depo- 
sition, whereby  the  sediment  had  time  to  partially  harden. 
The  former  denote  a  shorter  time,  so  that  the  laminse, 
in  general,  do  not  easily  separate  from  each  other.  In. 
some  stones  it  requires  as  much  force  to  split  them 
along  the  planes  of  lamination  as  "across  the  grain." 
The  different  kinds  of  lamination  are  instructive,  since 
they  indicate  the  circumstances  under  which  the  rock 


80 


LITUOLOGICAL      GEOLOGY. 


was  formed.  Quiet  deposition  always  produced  parallel, 
slowly  rippling  waves,  curved,  and  pressure,  contorted 
lamination. 

5.  faults. — Vertical  cracks  or  seams  frequently  trav- 
erse the  rocks,  and  the  strata  on  one  side  slipping  away 
from  those  on  the  other,  the  layers  on  the  two  sides  do 
not  correspond.  During  the  unequal  movements  which 
have  produced  the  dislocation,  the  edges  have  often 
ground  together  so  as  to  become  polished  and  grooved. 
Fig.  24  represents  a  series  of  faults,  offsets,  as  they  are 
called,  in  the  iron  mine  at  Mt.  Pleasant,  N.  J. 

FIG.  24. 


Faults  (offsets)  in  Mt.  Pleasant  Iron  Mine,  Rockaway,  N.  J. 

6.  Jointed  Structure.— -When  these  vertical  cracks 
are  parallel  to  each  other,  and,  in  addition,  a  second 
system  crosses  the  first  at  right  angles,  the  rocks  are 
divided  into  regular  blocks,  forming  a  jointed  structure. 
On  Cayuga  Lake  the  rocky  bluifs  resemble  fortifications 


STRUCTURE     OF     THE     ROCKS. 


81 


with  towers  and  bastions.  Joints  in  the  rocks  are  almost 
invaluable  to  the  quarrymen.  It  would  be  a  most  diffi- 
cult task  indeed  to  quarry  a  rock  destitute  of  stratifica- 

FIG.  25. 


Jointed  Structure,  Cayuga  Lake. 

tion  and  joints.  These  seams  have  doubtless  been  pro- 
duced partly  by  shrinkage  as  the  earth  has  cooled,  and 
partly  also  by  long-continued  lateral  pressure  consequent 
upon  movements  of  the  earth's  crust.  The  fact  that  the 
joints  of  any  region  are  parallel  to  each  other  indicates  a 
common  origin. 

7.  Folds.  —  Strata  are  often  so  folded  upon  each 
other  that  it  is  difficult  to  decide  upon  their  relative  age. 
Huge  mountains  consist  of  rocks  twisted  and  contorted 
as  if  they  had  been  "crumpled  up"  by  some  mighty 
hand.  Fig.  26  represents  a  section  of  slate  1000  feet 
long  and  300  feet  high,  taken  in  the  coast  ranges  of 
California.  After  these  were  deposited  as  sediment,  they 
were  crushed  together  and  bent  over  by  steady  lateral 


82 


LITHO  LOGICAL      GEOLOGY. 


pressure.*     "  How  prodigious  the  force  which  could  fold 
the  rocky  strata  of  a  mountain  as  one  would  the  leaves 

FIG.  26. 


FIG.  27. 


Flexures  in  Slate,  Coast  Range,  California. 

of  a  book."  After  rocks  have  been  folded  in  this  man- 
ner, the  top  has  often  been  removed  by  denudation^ 
i.  e.,  the  action  of  water,  leaving  parallel  strata  standing 
on  edge,  the  older  or  lower  being  above  the  newer. 
Thus,  in  Fig.  27,  if  the 
fold  were  swept  off  down 
to  the  line  D  E,  there 
would  be  no  appearance 
of  anything  more  than  a 
mere  tilting  up  of  the 
strata;  yet  the  layer  A 
would  lie  above  C,  when  it  was  really  deposited  be- 
low it. 


B          C  A        B 

A  Decapitated  Fold. 


*  Lyell  illustrates  the  effects  which  pressure  would  produce  on  flexible  strata 
by  laying  several  pieces  of  cloth  upon  each  other  in  a  pile,  and  then  placing  a 
book  on  top ;  apply  other  books  at  each  end  and  force  them  toward  each  other. 
The  folding  of  the  cloth  will  exactly  imitate  the  folding  seen  in  the  rock  strata. 

t  Near  Cfcambersburg,  Pa.,  there  is  a  fault  20  miles  in  length,  and  the  depth  of 
the  dislocation  is  20,000  feet,  and  yet  a  man  can  stand  with  one  foot  on  one  side 
of  this  fracture  and  the  other  foot  on  the  other  side.  What  has  become,  then,  of 
this  immense  mass  of  material  20,000  feet  in  height .  It  must  have  been  swept 
into  the  Atlantic  by  the  denuding  flood.  If  this  had  not  been  done,  a  bold 
precipice  would  have  stood  there  nearly  four  miles  in  height  and  twenty 
miles  in  length.  Long  ages  must  have  been  required  for  water  to  effect  such  a 
denudation.  —Lesley. 


STRUCTURE     OF    THE     ROCKS.  83 

•  8.  Concretions  are  rounded  nodules  formed  by  the 
tendency  of  matter  to  collect  about  a  center.  They  are 
usually  flattened,  though  they  are  sometimes  quite  spher- 
ical. At  the  center  there  is  most  commonly  some  foreign 
object,  a  fossil,  shell,  twig,  or  the  like,  which  was  the 
nucleus  of  the  crystallization.  In  some  iron  mines  are 
found  balls  of  ore,  which,  from  their  peculiar  form, 
are  termed  "kidney  shaped."  Calcareous  concretions, 
washed  up  by  the  waves,  abound  along  the  shores  of 
Lake  Erie.  They  have  been  found  as  large  as  six  feet 
in  diameter.  They  sometimes  have  the  shape  of  large 
sea-turtles,  and  the  cracks  formed  by  shrinkage  often  re- 
sembling the  plates  of  the  shell,  they  are  considered  by 
the  neighboring  people  as  petrified  relics  of  that  animal. 
On  the  coast  of  Durham,  England,  the  magnesian  lime- 
stone forms  bold  cliffs,  which  look  as  if  made  up  of  irreg- 
ularly piled  cannon  balls.  "When  the  internal  cracks 
formed  in  drying  have  become  filled  with  spar,  the  con- 
cretions are  termed  septaria  (septum,  a  division),  and, 

FIG.  28. 


Claystone,  Springfield,  Mass. 

when  cut  and  polished,  present  an  ornamental  appear- 
ance.    They  are  so  abundant  as  to  be  used  in  making  the 


84  LITHOLOGICAL     GEOLOGY. 

famous  Eoman  cement..  In  beds  flf  clay  containing  con- 
siderable carbonate  of  lime  are  found  peculiar  concretions 
called  claystones.  They  are  popularly  supposed  to  be 
worn  by  the  water.  They  often  assume  most  fantastic 
shapes,  resembling  familiar  objects,  such  as  a  hat,  bird, 
ring,  etc.  A  variety  of  limestone  composed  of  minute 
concretions,  often  as  small  as  a  grain  of  sand,  is  termed 
oolitic  (see  Fig.  7).  Along  the  limestone  bluffs  of  the  Mis- 
sissippi beautiful  "geodes"  are  found.  Externally  they 
are  merely  rough  stones,  but  a  blow  of  the  hammer  re- 
veals the  interior  lined  with  delicate  quartz  crystals.* 
Fig.  29  represents  iron  nodules,  found  in  coal  mines, 

FIGS.  29-3 


^BP 

Ironstone  Nodules,  showing  Varieties  of  Central  Nuclei. 

with  their  central  nuclei — No.  1,  a  fragment  of  a  plant ; 
2,  a  fish-tooth ;  3,  a  coprolite  (fossil  excrement) ;  and  4, 
a  septarium,  with  curious  partitions  of  white  carbonate  of 
lime,  giving  the  section  the  appearance  of  a  beetle ;  from 
which  circumstance  such  nodules  are  known  in  some 
places  as  beetle  stones. 

*  "  Water  is  sometimes  found  in  the  geodes,  holding  the  silex  in  solution, 
and  making  with  itXjnilky  looking  mixture.  As  the  water  evaporates,  the 
eilex  has  been  known  to  suddenly  form  into  delicate  crystals.  Such  geodes 
were  at  one  time  abundantly  found  on  Briar  Creek,  in  Scriven  or  Burke  County, 
Ga.,  in  a  rock  composed  of  hornstone  and  jasper;  the  milky  fluid  contained  in 
them  was  used  by  the  inhabitants  as  a  paint  or  whitewash."— Am.  Journal  of 
Science. 


STRUCTURE     OF     THE     ROCKS. 


85 


9.    Slate  Structure. — This  term  is  commonly  ap- 
plied to  any  rock  which  splits  into  thin  layers.     The  true 

FIG.  33. 


Section  exhibiting  Lines  of  Cleavage. 

slate,  however,  splits  in  layers  transverse,  often  at  right 
angles  to  the  strata.  Such  rocks  have  been  changed  from 
clay  shales  by  metamorphic  action,  in  which  process  they 
have  been  hardened  and  partially  crystallized,  while  at 
the  same  time  they  have  been  submitted  to  long-con- 
tinued lateral  pressure.  Prof.  Tyndall  has  shown  that 
even  soft  clay  will  in  this  manner  divide  into  thin 
laminae. 

(2.)    UNSTRATIFIED    ROCKS. 

The  unstratified  rocks  are  found  as  shapeless  masses 
underlying,  overlying,  and  sometimes  penetrating  the 
stratified  rocks. 

/.  ^Definitions. — In  Fig.  34,  C  is  an  underlying 
mass  of  granite,  e  is  a  stratum  forced  between  two 


FIG.  34. 


c  B  A 

strata  of  sedimentary  rocks,  d  is  an  overlying  mass,  and 


83 


LITHOLOGICAL     GEOLOGY. 


A  simply  a  mass  thrown  up  from  below,  and   disrupt- 
ing the  regular  stratified   rocks   above  it.      In   Fig.  35, 

FIG.  35. 


at  c  is  a  fault  in  the  rocks,  and  the  joint  at  that  point 
filled  with  igneous  rock  is  called  a  dike.  At  a  is  a  series 
of  veins  traversing  a  stratified  and  an  unstratified  rock. 

2.  Yeins  are  fissures  in  the  rock  strata,  filled  with 
crystallized  mineral  matter,  such  as  fluor  spar,  quartz, 
etc.    They  are  of  all  sizes,  from  an  inch  to  many  feet 
in  thickness.     We  often  find  rocks  and  even  pebbles 
crowded  with  veins  sometimes  not  thicker  than  a  sheet 
of  paper  (see  Fig.  39). 

3.  tDifces  are  wide  fissures  filled  with  igneous  rocks 
or  recent  lava.     They  are  generally  larger  than  veins, 
have  their  sides  more  nearly  parallel,  ramify  less  com- 
monly in  branching  veins,  and  contain  but  a  single  kind 
of  rock.     In  Fig.  36  is  a  representation  of  modern  dikes 
•near  Mt.  Etna.     The  term  dike  means  a  wall.     It  is  de- 
rived from  the  fact  that  the  trap  is  generally  harder  than 
the  adjacent  rock,  and  hence  disintegrates  more  slowly 
when  exposed  to  the  elements.     The  dike  thus  projects 
above  the  surface  like  i  wall,  often  traversing  the  coun- 
try for  many  miles.     Hugh  Miller,  in  speaking  of  the 


STRUCTURE     OF     THE     ROCKS. 

FIG.  36. 


87 


Modern  Dikes  near  Mt.  Etna. 


scenery  about  Edinburgh,  compares  the  denuding  influ- 
ences to  the  work  of  the  sculptor;  as  he  brings  out  his 

FIG.  37. 


Trap  Dike,  Lake  Superior. 


88 


LITHOLOGICAL      GEOLOGY. 


FIG.  38 


figures  in  relief  by  cutting  away  about  them,  so  Time 
scoops  away  the  sand  rock  and  shale,  and  leaves  the  bold, 
rugged  features  of  the  trap  ridges. 
When  veins   cross  each   other,  it  is   easy  to   decide 

upon  their  relative 
age,  the  one  which 
is  separated  being 
necessarily  the  older. 
Thus  in  Fig.  38 
there  is  a  trap-dike 
protruding  through 
a  bed  of  gneiss,  and 
crossing  that  is  a 
vein  of  quartz,  a  #. 
Prof.  Hitchcock  de- 
scribes a  block  of  greenstone  which  exhibits  eleven  series 
of  veins. 


Dike. 

a  b.   A  Quartz  Vein  passing  through  a  Greenstone 
Dike  and  Layers  of  Gneiss. 


^.    Origin   of  Yeins   and  3)Mes.—When  the 

rocks  cooled  from  a  melted,  or  dried  from  a  moist  state, 
they  naturally  shrank  so  as  to  form  cracks  or  seams 
of  varying  size.  In  different  ways  Nature  collected 
material  to  fasten  the  rocks  together  again.  Some  clefts 
were  filled  by  melted  rocks  injected  from  below,  and  then 
cooled.  This  is  known,  because  the  adjacent  rocks  are 
metamorphosed  by  contact  with  the  burning  mass,  and 
wear  a  different  look  from  the  rest,  while  the  mass  itself, 
by  its  crystallization,  shows  that  it  cooled  sooner  on  the 
outside  against  the  walls  than  at  the  center.  Dikes  pass- 
ing through  beds  of  chalk  in  the  county  of  Antrim,  in 
the  north  of  Ireland,  have  changed  the  chalk  to  mar- 
ble. Some  seams  were  filled  by  chemical  processes  with 


STRUCTURE     OF     THE     ROCKS. 


89 


matter  which  crystallized  out  from  the  adjacent  rocks, 
as,  for  example,  a  plaster  rock  dark  and  muddy  is  often 
found  crossed  with  layers  and  filaments  of  white,  trans- 
parent selenite  crystals,  which  have  doubtless  been  formed 
from  the  parent  stone.  The  larger  number,  however,  of 
these  rents  were  mended  with  rock  material  from  highly- 
heated  water  charged  with  mineral  matter.*  This  water 
filtering  through  the  finest  seams  of  the  rock  would  fill 
them  with  a  crystalline  paste.  We  often  see  this  process 


FIG.  39. 


Vein-form  Pebble  from  Drift,  Elmira. 


*  Large  rocks  are  sometimes  as  full  of  veins  as  your  hand  is,  and  of  veins 
nearly  as  fine  (only  a  rock-vein  does  not  mean  a  tube  but  a  crack).  These  clefts 
are  mended  usually  with  the  strongest  material  the  rock  can  find,  and  often 
literally  with  threads ;  for  the  gradually  opening  rent  seems  to  draw  the  sub- 
stance it  is  filled  with  into  fibers  which  cross  from  one  side  to  the  other,  so 
that  when  the  crystals  become  distinct,  the  fissure  has  often  the  look  of  a  rent 
brought  together  with  strong  cross  stitches.  ^When  all  has  been  fastened,  a  new 
change  of  temperature  may  occur,  and  the  roc^-contract  again.  The  old  vein 
must  open  or  a  new  one  be  formed.  If  the  old  one  be  well  filled  the  cross 
stitches  will  be  too  strong  to  break,  so  that  it  can  only  give  away  at  the  sides; 
and  thus  this  space  being  filled  afterward,  a  supplementary  vein  is  added.  In 
this  manner  three  or  four  parallel  veins  have  been  made.— Buskin. 


90 


LITHO LOGICAL      GEOLOGY. 


FIG.  40. 


beautifully  illustrated 
in  an  opaque  uncrys- 
talline  rock,  and  in 
pebbles  threaded  with 
fine  crystalline  veins 
of  a  different  variety. 
(Fig.  39.)  Veins  are 
often  rich  in  metallic 
ores.  Probably  the 
metal  in  such  cases 
has  been  sublimed  by 
heat  below,  and  car- 
ried up  either  with 
steam  or  melted  mat- 
ter, and  deposited  in 
the  rock  fissures 
above.  In  the  figure 
is  shown  a  valuable 
vein  of  lead-ore  for- 
merly worked  at  Ros- 
sie,  K  Y.  This  is 
the  simplest  form  of 
a  metallic  vein  (lode), 
as  it  is  a  mere  vertical 
sheet. 


Lead  Vein  of  Rossie,  N.  Y, 


ef  The  crust  of  our  earth  is  a  great  cemetery,  where  the  rockt 
are  tombstones  on  which  the  buried  dead  have  written  theit 
own  epitaphs.3'— AGASSIZ. 


THE  history  of .  the  formation  of  the  earth's  crust  is 
not  yet  fully  written.  In  its  investigation  many  diffi- 
culties are  met.  Strata  were  not  made  over  the  whole 
earth  at  the  same  time,  so  that  the  coatings  of  rock  are 
not  uniform.  Again,  some  are  found  in  one  section 
which  are  wanting  in  others,  and  the  same  strata  even 
are  composed  frequently  of  diverse  material  in  different 
parts  of  the  earth.  Thus,  the  chalk  formation  of  Eng- 
land is  represented  by  a  limestone  in  this  country, 
though  both  belong  to  the  same  era.  It  is  therefore  a 
difficult  task  to  reconstruct  these  scattered  fragments, 
and  put  them  together.  "  The  world  is  to  the  geologist 
a  great  puzzle  box."  He  is  to  trace  the  resemblances 
and  learn  how  to  combine  all  the  widely  strewn  parts  of 
the  world's  history,  and  to  arrange  them  in  order  and 
symmetry.  He  is,  however,  constantly  learning  to  read 
more  accurately  the  rocky  leaves  of  the  book  of  nature. 
In  his  work  the  fossils  are  his  chief  reliance.  They  have 
been  well  termed  "the  Medals  of  Creation,"  since  by 
their  means  the  geologist  identifies  different  strata,  and 


94  HISTORICAL     GEOLOGY. 

judges  of  the  successive  creations  of  animals  and  plants 
through  the  ages  of  the  past.  •  As  the  seals,  medals,  coins, 
etc.,  found  in  a  ruined  city  concerning  which  history  is 
silent,  declare  its  nationality,  so  the  organic  remains  of  a. 
stratum  determine  its  geologic  period  and  characteristics. 
Each  epoch  recorded  in  its  rocks  and  fossils  the  history 
of  the  life  which  it  supported,  and  the  changes  through 
which  it  passed.*  Each  formation  possesses  its  peculiar 
fossils.  This  similarity  obtains  in  a  great  degree  over  the 
entire  world.  Thus,  the  identification  of  fossils  is  the 
identification  of  formations.  We  can  therefore  under- 
stand with  what  eagerness  these  are  gathered  and  pre- 
served. Fragments  which  the  ignorant  would  spurn 
from  his  feet  are  invested  with  as  high  an  interest  as  the 
obelisks  of  Egypt  or  the  sculptures  of  Nineveh.  The 
antiquarian  pores  over  those  with  intensest  enthusiasm, 
seeking  to  read  the  history  of  a  few  thousand  years.  The 
geologist  bends  with  equal  delight  over  the  forms  and 
impressions  of  the  rocks,  seeking  to  gather  information 
with  regard  to  a  past,  compared  to  the  duration  of  which 
the  chronology  of  man  is  but  as  the  moments  of  yester- 
day. The  print  of  a  leaf,  a  petrified  shell,  a  tooth,  the 
fragment  of  a  bone,  a  fish-scale  even,  may  serve  to  un- 
riddle the  most  puzzling  problem.  Eough  and  mutilated 


*  "  Nature  has  all  her  facts  stereotyped.  She  writes  her  events  often  upon  the 
most  fragile  plants  and  flowers,  on  the  very  winds  and  waters— all  the  most 
evanescent  and  changing  forms,  as  well  as  the  most  permanent.  Her  record  is 
as  enduring  as  the  phases  of  the  object  upon  which  she  writes,  and  sometimes, 
as  if  fearing  both  would  be  lost,  she  petrifies  the  whole,  and  leaves  it  thus  to 
endure  for  the  ages.  She  has  often  preserved  in  stone  the  history  of  her  frailest 
leaves,  her  most  ephemeral  and  minutest  insects  and  infusoria,  the  record  of  her 
ebbing  and  flowing  tides,  of  the  piles  of  dust  blown  together  by  her  winds,  the 
footprints  of  her  smallest  birds,  and  of  her  rain-drops  falling  upon  the  sand."— 
Blackwell. 


HISTORICAL      GEOLOGY.  95 

though  the  fragments  may  be,  to  the  educated  eye  they 
embody  a  tale  as  legible  as  any  sculpture  or  hieroglyph- 
ics, and  far  more  comprehensive.  That  tiny  stem,  a, 
mere  discoloration  on  the  rock,  once  floated  as  sea-weed 
in  the  waters;  that  reed  once  luxuriated  in  a  primevd 
marsh ;  that  delicate  rock  impression  was  a  fern  thri 
once  waved  in  the  sunshine ;  and  that  simple  leaf,  nov: 
only  a  film  of  coal-like  matter,  sparkled  with  the  dew  of 
heaven  as  certainly  as  the  tender  herb  is  cherished  by  the 
dew  to-day,  or  existing  verdure  grows  to  beauty  in  the 
sunlight.  Every  trace,  then,  becomes  a  letter,  every 
fragment  a  word,  every  perfect  fossil  a  chapter  in  the 
world's  history.  Each  tells  of  races  that  lived,  multi- 
plied and  died,  of'  lands  that  were  tenanted,  and  waters 
thronged  with  life, — so  oft  repeated,  again  and  again,  that 
the  mind,  at  first  excited  by  the  marvels,  at  last  grows 
weary  and  loses  itself  in  the  contemplation  of  the  works 
of  the  Infinite  Creator. 

There  are  no  sharply-drawn  lines  between  the  different 
ages.  They  fade  into  each  other  as  insensibly  as  the 
mountain  blends  with  the  plain.  Yet  each  has  a  promi- 
nent idea,  and  chronicles  a  grand  transition  in  the  world's 
history.*  Lesser  changes  are  denoted  by  Periods,  Epochs, 
and  Groups.  Some,  at  least,  of  the  revolutions  marking 
the  separate  ages  were  nearly  if  not  quite  universal. 
Those  denoting  the  other  divisions  were  more  local  in 
their  character.  The  periods  and  epochs  are  therefore 


*  The  land  now  lay  low  in  the  water,  and  anon  was  lifted  into  arid,  moun- 
tainous regions.  Consequent  upon  each  change  was  a  new  set  of  climatic  influ- 
ences, winds,  ocean  currents,  rains,  etc.,  each  necessarily  producing  its  impress 
on  the  vegetable  and  animal  life  of  the  period.  Thus  there  were  pauses,  as  it 
were,  in  the  deposition  of  sediment,  each  pause  making  a  break  in  the  strata. 


96  HISTORICAL       GEOLOGY. 

not  the  same  in  Europe  and  America.  They  vary  much 
in  the  formations  which  are  represented  even  on  the 
Atlantic  slope  and  in  the  Mississippi  valley. 

Geological  ^Divisions.  —  The  first  land,  swept  by 
a  boiling  ocean,  was  lifeless.  The  age  during  which  it 
was  formed  has  received  a  corresponding  name,  The 
Azoic  TIME  (without  life).  Following  this,  we  have 
the  successive  stages  in  the  -development  of  life  on  the 
globe. 

As  the  history  of  man  upon  the  earth's  crust  is  di- 
vided into  three  portions,  Ancient)  Medieval,  and  Mod- 
ern history,  so  the  history  of  the  crust  itself  is  sepa- 
rated into  three  grand  eras,  the  Palceozoic  time  (ancient 
life),  the  Mesozoic  time  (middle  life),  and  the  Cenozoic 
time  (recent  life).  Under  these  are  classified  those  ages 
which  resemble  each  other  in  their  dominant  types  of 
life. 


I.      PALEOZOIC     TIME. 

1.  SILURIAN  AGE  (Age  of  Mollusks). 

2.  DEVONIAN  AGE  (Age  of  Fishes). 

3.  CARBONIFEROUS  AGE  (Age  of  Coal-Plants.) 


II.      MESOZOIC     TIME. 
THE  AGE  OF  REPTILES. 

III.      CENOZOIC     TIME. 

THE  AGE  OF  MAMMALS. 

The  following  table   contains  the  geological  subdivi 
sions  now  generally  received  : 


C 


? 

> 

& 
" 

•^ 

O 

2 

? 

^5 
w 

§ 

^3 

c: 

f 

Crt 

§. 

> 

•^ 

O 

§ 

/>! 
^/  ^' 

vO  O 

w 


£  £P 

^  s 

^    ^ 

s1 

P 

SILURIA 

UPPER 

C/) 

gS 

is 

3 

2  ^ 

CTl 

fe! 

)fr  .; 

?   2 

"d 

2  r* 

> 

a       « 

^ 

»  > 

0 

> 

7i 

> 

1    1 

1 

r  2 

3 

?  a- 

S3 

w  ^ 

2 

o       2 

s 

50  • 

o 

o       o 

CB 

a 

0 

w 

o 

• 

PI 

• 

71 

, 

• 

« 

o 

a 

. 

9S  HIS  T  O  R  1C  AL       G  EOLOG  Y. 

T/ie  ^Duration  of  Time  represented  by  these 
geological  periods  and  epochs  we  have  no  means  of  judg- 
ing. Estimating  the  past,  however,  by  the  present  rate 
of  change,  it  must  be  immense,  so  that  even  if  we  could 
express  it  in  centuries  and  years,  we  could  form  no  idea 
of  the  aggregate  any  more  than  we  can  comprehend  the 
distances  thut  separate  our  earth  from  the  fixed  stars. 
This  idea  of  immense  duration  of  time  is  suggested  at 
the  first  examination  of  the  stratified  rocks.  All  that 
Geology  attempts,  at  present,  is  to  arrange  in  regular 
order  the  -various  stages  of  progress  in  the  history  of 
the  earth's  crust,  leaving  it  for  the  future  to  decide 
upon  the  length  of  the  different  epochs.  As  yet  we 
only  know  that  "  time  is  long"  and  hence  estimate  it 
by  ages,  eras,  and  periods,  rarely  venturing  more  than 
an  occasional  hint  at  their  relative  duration.  There  is 
an  eternity  of  time  as  well  as  of  space  in  which  God 
works  out  His  almighty  plan  of  creation.  Whatever 
may  have  been  our  preconceived  notions,  we  should 
come  to  the  study  of  Nature  with  a  reverent,  teach- 
able spirit,  seeking  to  learn  its  mysteries,  to  compre- 
hend its  plan,  and  to  understand  the  ways  of  Him 
who  created  all  things. 


|HE    Szoi'c    fiME. 

^Location. — The  Azoic  rocks  probably  constitute  the 
foundation  rock  over  the  entire  globe,  but  are  generally 
covered  deeply  with  later  deposits.  On  our  continent 
they  form  the  surface  rock  of  a  V-shaped  region  resting 
on  the  great  lakes,  one  arm  reaching  N.W.  to  the  Arctic 


THE      AZOIC      TIME.  (JU 

Ocean,  and  the  other  N.E.  to  Labrador  ;  in  addition 
there  are  isolated  sections,  as  shown  in  the  map  (Fig. 
41).  These  constitute  the  oldest  dry  land  of  our  globe  — 
the  Canada  area  representing  tho  ancient  continent,  and 
he  other  portions  widely  scattered  islands.  America  is, 


FIG. 


Azoic  Continent  (D.ina). 


geologically  speaking,  the  old  rather  than  the  new  worir, 
Leing  the  first-born  among  the  continents.  "  We  may 
walk,"  says  Agassiz,  "along  its  summit,  and  feel  that  we 
are  treading  upon  the  granite  ridge  that  first  divided 
the  waters  into  a  Northern  and  a  Southern  ocean  ;  and 


100  HISTORICAL       GEOLOGY. 

if  our  imagination  carry  us  so  far,  we  can  look  down 
to  its  base,  and  fancy  how  the  sea  washed  against  this 
earliest  shore  of  a  lifeless  world." 

ICinds  of  ffiocfc.  —  .The  rocks  are  generally  mete- 
m  orphic,  such  as  granite,  gneiss,  etc.  Statuary  marble, 
schists,  porphyry,  soapstone,  slates,  and  the  like,  also  oc- 
cur. All  were  doubtless  deposited  as  sedimentary  strata 
from  the  washings  of  the  original  crust,  and  perhaps  also 
the  eruptions  of  submarine  volcanoes,  and  afterward 
crystallized.  The  iron  mountains  of  Missouri,  and  the 
iron-ore  beds  of  northern  New  York,  date  from  this  time. 


.  —  Of  the  life  of  this  era  we  know  nothing 
definitely,  except  that  if  any  existed  it  must  have  been 
of  the  lowest  order.  The  term  Azoic  indicates  that  the 
land  and  sea  were  devoid  of  inhabitants.  There  was, 
without  doubt,  such  a  time  when  the  boiling  water  and 
the  heated  earth  could  not  support  either  animal  or  vege- 
table life.  Some  of  the  slates  and  sandstones  are  not 
more  altered  than  rocks  of  a  later  period  which  abound 
in  'fossils,  so  that  organic  remains  may  reasonably  be 
sought.  Should  any  be  hereafter  definitely  discovered 
in  what  we  have  termed  the  Azoic  time,  this  will  simply 
remove  the  "  dawn  of  life  "  back  to  an  earlier  period. 

Logan  found  in  a  bed  of  marble,  near  the  Eiver  St. 
Lawrence,  what  seemed  to  be  fossil  corals.  Prof.  Daw- 
son,  of  Montreal,  after  a  careful  microscopic  examina- 
tion, pronounced  them  to  be  shells  of  Ehizopods  *  (root- 


*  They  were  so  called  because  the  shell  was  full  of  holes,  through  which 
passed  fleshy  filaments  or  sterna.  The  higher  orders  of  .these  animals  laid  hold 
of  objects  by  means  of  these  stems,  and  dragged  themselves  along.  The 
fpzoOn,  however,  simply  grew  in  patches  on  the  sea-bottom. 


THE      AZOIC      TIME. 


101 


footed).     The  name  Eozoon  Canadense  (Canadian  early 

life)  has  been'  given  to  this  remarkable  fossil.     Since  then 

it  is  said  to  have  been 

found  in   the   serpen-  IG'  42' 

tine  rocks  of  Chelms- 

ford,  Bolton,  Boxboro', 

and  at  many  other  lo- 

calities in    Massachu- 

setts. 

Still,  the  hypothesis 
of  the  organic  struc- 
ture of  these  remains 
is  not  universally  ac- 
cepted. Should  it  be 
established,  it  will  remove  the  beginning  of  life  back 
through  an  era  represented  by  30,000  feet  of  rocks. 


I 
itec^i 


NJttv- 

a.  b. 

a.  Serpentine  Marble  of  Canada. 

b.  Chamber- Wall  of  EozoOn   magnified  (Car- 

penter). 


.  —  /.  Mountains.  —  Between  Canada  and 
New  York  runs  a  low  range  of  hills  called  the  Lauren- 
tian,  named  from  the  River  St.  Lawrence.*  They  are 
probably  the  oldest  mountains  upon  the  earth. 


*  "Their  low  stature,  as  compared  with  that  of  other  more  lofty  mountain 
ranges,  is  in  accordance  with  an  invariable  rule,  by  which  the  relative  age  of 
mountains  may  be  estimated.  The  oldest  mountains  are  the  lowest,  while  the 
younger  and  more  recent  ones  tower  above  their  elders,  and  are  usually  more 
torn  and  dislocated  also.  This  is  easily  understood  when  we  remember  that  all 
mountains  and  mountain  chains  are  the  result  of  upheavals,  and  that  the  vio- 
lence ot  the  outbreak  must  have  been  in  proportion  to  the  strength  of  the 
resistance.  When  the  crust  of  the  earth  was  so  thin  that  the  heated  masses 
within  easily  broke  through  it,  they  were  not  thrown  to  so  great  a  height,  and 
formed  comparatively  low  elevations,  such  as  the  Canadian  hills  or  the  moun- 
tains of  Bretagne  and  Wales.  But  in  later  times,  when  young,  vigorous  giants, 
such  as  the  Alps,  the  Himalayas,  or,  later  still,  the  Rocky  Mountains,  forced 
their  way  out  from  their  fiery  prison-house,  the  crust  of  the  earth  was  much 
thicker,  and  fearful  indeed  must  have  been  the  convulsions  which  attended 
their  exit."—  Geological  SketcJies,  Agassiz. 


10, 


HISTORICAL      GEOLOGY. 


2 .  Convulsions. — The  metamorphism  of  the  Azoic 
rocks  was  closely  attended  by  extensive  upheavals,  which 
twisted  and  folded  them,  throughout  vast  areas,  into 
every  conceivable  form.  They,  however,  commonly  re- 
main in  regular  layers,  which  can  be  traced.  This  would 
indicate  a  uniform  force  acting  at  right  angles  to  the 
dip  of  the  beds.  These  movements  must  have  taken 
place  prior  to  the  Silurian  age,  since  the  Silurian  rocks 
rest  unconformably  upon  the  Azoic,  as  is  shown  in  the 
accompanying  figure.  We  see  here  that  the  sedimentary 


Unconformity  of  the  Lower  Silurian  with  the  Gneiss  at  Montmorency,  Canada  East 
€,  d,  C,  b.  Lower  Silurian,     a.  Gneiss.    /.  Black  Slate. 

rocks  c,  d,  c,  b,  lie  horizontally  upon  tilted  gneiss,  a,  and 
black  slate,  /.  The  Azoic  rocks  at  Montmorency  are 
about  12,000  feet  in  thickness.  Through  what  ages 
those  vast  deposits  must  have  slowly  gathered  in  the 
primeval  ocean!* 


*  In  the  Azoic  rocks  are  conglomerates  bearing  no  resemblance  to  the  beds 
in  which  they  are  found.  They  are  fragments  of  other  rocks,  other  continents 
perhaps,  broken  up  and  destroyed.  There  is,  then,  little  hope  of  our  discover- 
ing the  origin  of  life  on  the  globe,  since  this  page  of  the  genesis  of  the  facts  has 
been  torn.  For  some  years  geologists  loved  to  rest  their  eyes  in  this  long  night 
of  ages  upon  an  ideal  limit,  beyond  which  plants  and  animals  would  cease  to 
Now,  this  line  of  demarcation  between  the  rocks  which  are  without 


THE     AZOIC     TIME.  103 

3.  Canadian  ^Divisions.  —  The  Azoic  rocks  of 
Canada  have  been  divided  by  Logan  into  two  distinct 
systems,  the  Laurentian  and  the  Huronian.  They  have 
a  total  thickness  of  about  30,000  feet.  The  former  in- 
cludes nearly  all  the  Azoic  area  ;  the  latter,  a  section  near 
Lake  Huron. 


of  £ife.—  The  presence  of  lime- 
stone, graphite   and  anthracite  coal  would  indicate  tha 
existence  of  life.     It  would  seem  reasonable  to  suppose 
x   that  vegetable  life  had  the  precedence,  since  the  animal 
1  kingdom  is  wholly  dependent  on   the  vegetable  for  its 
subsistence;  and  that  the  vegetation  consisted  of  land- 
plants,  since  -the  earth  would  be  cooled  sufficiently  to 
admit  of  life  sooner  than  the  water.     Geology  is,  how- 
ever, as  yet  silent  on  this  subject,  and  no  plants  of  that 
period  are  known. 

5.  The  Outlines  of  tfie  Continent.—  This  V-- 
shaped Azoic  land  was  the  nucleus  around  which  the 
continent  grew.  Through  the  subsequent  ages  addi- 
tions were  made  to  this  germ  upon  the  southeast  and 
southwest  sides.  Its  very  shape  was  thus  a  prophecy  of 
the  shape  of  North  America.  The  direction  of  the  two 


vestiges  of  organized  beings  and  those  which  contain  fossils  is  nearly  effaced 
among  the  surrounding  ruins.  On  the  horizon  of  the  primitive  world  we  eeo 
vaguely  indicated  a  series  of  other  worlds  which  have  altogether  disappeared ; 
perhaps  it  is  necessary  to  resign  ourselves  to  the  fact  that  the  dawn  of  life  is  lost 
in  this  silent  epoch  where  age  succeeds  age  till  they  are  clothed  in  the  garb  of 
eternity.  The  river  of  creation  is  like  the  river  Nile,  which,  as  Bossuet  says, 
hides  its  head — a  figure  of  speech  which  time  has  falsified  ;  but  the  endless  spec- 
ulations opened  up  by  these  and  similar  considerations  led  Lyell  to  say :  "  Ktere 
I  am  almost  prepared  to  believe  in  the  ancient  existence  of  the  Atlantis  ^f 
Plato."— M.  Esquiros. 


104  HISTORICAL      GEOLOGY. 

arms  was  parallel  to  that  of  the  Atlantic  and  Pacific 
oceans  (see  Fig.  41).  The  land  and  sea  have  from  the 
beginning  maintained  these  relative  positions.  We  are 
thus  led  to  believe  that  the  thought  of  God,  as  ulti- 
mately revealed  in  the  form  of  this  continent,  was  fairly 
outlined  in  the  first  land  that  appeared.  In  the  early 
part  of  the  next  age  the  Appalachian  and  Kocky  moun- 
tains began  to  rise,  thus  forming  the  framework  of  the 
continent,  and  still  further  developing  the  plan. 

How  accurately  did  the  ancient  "  backbones  "  define  the 
present  contour  of  the  finished  continent !  The  St.  Law- 
rence flows  to  the  sea  through  a  valley  parallel  to  the 
Laurentian  ridge ;  the  Mississippi  river  in  a  second  valley 
inclosed  between  the  Appalachian  and  Eocky  mountains ; 
the  Mackenzie  finds  its  way  to  the  Arctic  sea  in  a  third 
valley  .between  the  Eocky  and  Laurentian  mountains; 
while  Hudson's  Bay  is  snugly  locked  in  the  arms  of  the 
Laurentian  mountains. 

6.  2*he  Mosaic  Accotmt  informs  us  that  on  the 
third  day  the  waters  were  gathered  into  one  place  and 
the  dry  land  appeared,  and,  as  a  later  creation  of  the 
same  day,  that  vegetation  was  brought  forth.  The  geo- 
logic record  of  the  Azoic  age  agrees  with  the  first  por- 
tion, and  upon  the  second  gives  as  yet  only  hints  of 
possible  discoveries.  The  direct  rays  of  the  sun  could 
not  penetrate  the  thick  mists  which  then  enshrouded  the 
warm,  damp  earth,  and  hence,  although  the  sun  and 
moon  had  shone  since  the  first,  these  luminaries  were  net 
yet  set  in  the  firmament  to  rule  the  day  and  the  night. 


THE     AZOIC     TIME. 


105 


[The  following  leaf  of  Natural  History  is  inserted  for  the  bene- 
fit of  those  pupils  who  may  not  be  familiar  with  that  delight- 
ful branch  of  knowledge.  This  brief  analysis  will  enable  us 
to  speak  more  understandingly  of  the  ancient  life  of  our  globe. 
It  may  be  studied  separately  or  used  merely  for  reference.] 


TPE  A  NIMAL 

K  IN'  'DOM. 


[Sub-kingdoms.] 


I.  VERTEBRATES.- 


[Classes.] 

i.  Mammals. 
2.  Birds. 
3.  Reptiles. 

4.  Fishes  .  .  . 

[Orders.] 

f  (i)  Teliosts. 
•{  (2)  Ganoids. 
1(3)  Selachians. 

fi.  Insects. 

II.  ARTICULATES.  •{  2.  Crustaceans. 
1 3.  Worms. 


Ill,    MOLLUSKS  .  . 


IV.  RADIATES  .  . 


1.  Cephalopods. 

2.  Gasteropods. 

3.  Pteropods. 

4.  Brachiopods. 

5.  Conchifers. 

6.  Bryozoans. 


i.  Echinoderms.  \  (2 


2.  Acalephs. 

3.  Polyps. 


1(3 


Echinoids. 
Star-fishes. 
Crinoids. 


All  animals  are  constructed  upon  one  of  four*  different 
types  which  constitute  the  sub-kingdoms  of  the  animal 
creation.  Each  type  is  a  thought  of  God  worked  out  in  a 
multitude  of  ways.  The  design  of  nature  seems  to  be  to 
have  an  infinity  of  detail  and  variety,  with  the  utmost 
simplicity  of  elements,  or,  as  Agassiz  beautifully  says,  a 
fundamental  harmony  upon  which  an  endless  set  of  vari- 


*  Some  authorities  give  a  fifth  class,  which  includes  what  are  termed  Proto- 
zoans, or  systemless  animals.  It  embraces  sponges,  infusoria,  and  other  similar 
animals  which  seem  to  have  no  distinct  plan  of  structure. 


106  HISTORICAL      GEOLOGY. 

ations  may  be  played.  It  is  our  privilege  to  trace  out 
these  four  ideas  in  their  curious  ramifications,  and  thus 
classify  the  animals  of  the  present  as  well  as  the  fossils  of 
the  past. 

I.  Sub- kingdom   of  Tertebrales. — The  verte 
brate  is  the  highest  type  of  structure.     Fishes,  reptileg, 
birds  and  man  all  agree  in  having  an  axis  running  from 
one  end  of  the  body  to  the  other,  which  in  the  lowest  an- 
imals is  a  soft  cord,  but  in  most  is  a  series  of  small  bones 
(vertebrae),  making  what  we  call  a  backbone.    The  spinal 
cord  lies  above  this,  and  expands  at  one  end  into  a  brain. 
This  sub-kingdom  is  divided  into  four  classes — MAMMALS, 
BIRDS,  EEPTILES,  and  FISHES.    Fishes  are  subdivided  into 
three  orders — Teliosts,  Ganoids,  and  Selachians. 

The  Teliosts  (telios,  complete,  and  osteon,  a  bone)  in- 
clude common  fishes  having  a  bony  skeleton.  Ex.,  perch, 
salmon,  etc. 

The  Ganoids  (ganos,  splendor)  comprise  fishes  covered 
with  enameled  scales.  Ex.,  sturgeon,  garpike,  etc. 

The  Selachians  (selachos,  cartilage)  embrace  those  hav- 
ing a  cartilaginous  skeleton  and  a  rough  skin,  often 
called  shagreen.  Ex.,  shark. 

II.  Sub -kingdom  of  Articulates. — The  articu- 
late type  is  a  jointed  structure,  i.  e.,  one  composed  of 
rings.     Ex.,   spider,    centipede,   shrimp,   etc.     It  is  ex- 
pressed in  three  different  ways,  and  thus  there  are  three 
classes — INSECTS,   CRUSTACEANS,  and  WORMS.     Crusta- 
ceans have  a  shelly  covering.    Ex.,  crab,  lobster,  etc. 

III.  Stib- kingdom  of  Molhisks. — The  mollusk 
type  is  a  soft  sack,  usually  inclosed  in  a  hard  shell.    Ex., 


THE     AZOIC     TIME.  107 

oyster,  clam,  etc.  There  are  six  classes — CEPHALOPODS, 
GASTEROPODS,  PTEROPODS,  BRACHIOPODS,  CONCHIFERS, 
and  BRYOZOANS. 

The  CEPHALOPODS  (head-footed)  have  arms  attached 
to  their  head.  Ex.,  nautilus,  cuttle-fish,  etc. 

The  GASTEROPODS  (body-footed)  move  on  the  under 
part  of  their  body,  which  forms  a  fleshy  foot.  Ex.,  snail, 
slug,  etc. 

The  PTEROPODS  (wing-footed)  live  only  in  the  sea,  and 
swim  with  a  pair  of  fins  extending  out  like  wings  from 
the  side  of  the  head.  They  are  the  food  of  the  right  whale. 

The  BRACHIOPODS  (arm-footed)  are  bivalves  having 
arms  by  which  they  stir  the  water,  and  thus  bring  their 
food  within  their  reach.  The  two  parts  of  the  shell  are 
unequal ;  the  larger  is  called  the  ventral  and  the  smaller 
the  dorsal  valve.  Each  valve  is,  however,  equal  sided,  so 
that  if  a  line  be  dropped  from  the  beak  to  the  opposite 
side,  it  will  divide  the  valve  into  equal  parts. 

The  COISTCHIFERS  have  their  gills  in  thin,  membranous 
plates  on  each  side  of  the  body,  which  may  be  easily  seen 
in  the  oyster,  clam,  etc.  (For  this  reason  they  are  some- 
times called  Lamellibranchs,  lamella,  a  plate.)  A  line  let 
fall  as  in  the  case  of  the  brachiopods,  will  divide  the  shell 
into  two  unequal  parts. 

The  BRYOZOAXS  (moss-like  animals)  grow  in  clusters, 
and  form  moss-like  incrustations  on  rocks.  They  re- 
semble corals. 

IT.  Sub- kingdom  of  Hadiales.—^z  radiate 
type  is  a  structure  arranged  around  a  central  axis.  Ex., 
star-fish.  There  are  three  classes — ECHIKODERMS,  ACA- 
LEPIIS,  and  POLYPS. 


108  HISTORICAL     GEOLOGY. 

The  ECHINODEKMS  (hedge-hog  skin)  are  covered  with 
spines.  They  are  divided  into  three  orders:  (1)  The 
EcliinoidSy  which  have  a  hard  shell,  as  sea-urchins  and 
the  like;  (2)  Star-fishes ;  and  (3)  Crinoids,  or  " stone- 
lilies,"  as  they  are  called,  since  they  grow  on  a  stem  like 
a  flower. 

The  ACALEPHS  (headless)  are  soft,  jelly-like  animals. 
Ex.,  jelly-fish,  medusa.  Some  of  them,  however,  formed 
corals,  and  have  hence  left  remains  among  fossils. 

The  POLYPS  (many-footed)  are  the  true  coral-produ- 
cing animals.  They  have  a  mouth  around  which  is  ar- 
ranged a  row  of  tiny  arms,  like  the  petals  of  a  China 
aster.  The  coral  is  the  bone  of  the  polyp,  which  it 
secretes  from  the  water.  As  the  animal  dies  below,  it 
leaves  its  skeleton  of  bone  behind,  and  grows  above. 


• — ^~~JZrJ^S4pr4sr*^^. 


I  HE  «?ALJEOZOIC  IIME. 

\^y  "XiL?  \1^) 

/  i.  Silurian  Age. 
PALAEOZOIC  TIME.  J  2.  Devonian  Age. 

(  3.  Carboniferous  Age. 

The  Palaeozoic  time  is  divided  into  three  ages  to  mark 
the  great  life-changes  which  occurred.  These  are  called 
the  Silurian  or  Age  of  mollusks,  the  Devonian  or  Age 
of  fishes,  and  the  Carboniferous  or  Age  of  coal-plants. 
These  ages,  though  unlike  in  marked  particulars,  are  yet 
distinguished  by  certain  common  features  in  the  life  they 
supported,-  while  they  are  all  very  dissimilar  to  any  later 
formations.  Neither  birds  nor  mammals  were  known, 


THE     SILURIAN    AGE. 


109 


and  many  extensive  classes  of  animals  which  peculiarly 
characterized  these  ages  disappeared  with  them. 


I.    THE    SILURIAN    AGE. 


I.  SILURIAN  AGE 
(AGE   OF   MOLLUSKS.) 


1.  Potsdam  Period. 

2.  Trenton  Period. 

3.  Hudson  Period. 

1.  Niagara  Period. 

2.  Salina  Period. 

3.  Lower  Helderberg  Period. 


This  first  great  stage  in  the  progress  of  life  on  the 
globe  was  so  called  by  Murchison,  the  celebrated  English 
geologist,  who  first  fully  investigated  it  in  Wales,  and  so 
named  it  from  the  ancient  Silures,  a  tribe  of  Britons 
formerly  inhabiting  that  region.  The  subdivisions  of 
the  age  vary  greatly  in  different  portions  even  of  the 
United  States.  The  Silurian  and  Devonian  rocks  are 
very  distinctly  developed  in  New  York,  and  the  epochs 
established  in  the  geologic  survey  of  that  State  are  there- 
fore taken  as  the  basis  for  study  and  comparison.  In 

FIG.  44. 


Ideal  Section  of  the  New  York  Formations. 


Fig.  44  is  shown  an  ideal  section  extending  from  the 
Azoic  rocks  in  the  northeastern  part  of  the  State  to  the 
carboniferous  in  the  southern.  It  will  be  seen  that  the 


110  THE     SILURIAN    AGE. 

different  epochs  succeed  each  other  regularly.  The  dip 
of  the  strata  is  by  no  means  as  uniform  as  is  represented, 
nor  is  there  any  attempt  to  indicate  their  relative  thick- 
ness. This  illustrates  on  a  grand  scale  the  fact  stated  on 
page  77  concerning  the  method  of  geologic  study. 

We  shall  see  that,  with  each  period,  a  narrow,  irregular 
lolt  was  added  to  the  Azoic  area,  from  which,  as  a  germ, 
the  continent  grew  by  successive  additions. 

General  Characteristics. — It  is  probable  that  at 
this  early  day  the  Appalachians  on  the  east  and  the 
Eocky  Mountains  on  the  west  were  already  being  lifted 
above  the  floor  of  the  sea,  thus  rendering  the  interior  of 
the  continent  an  immense  lagoon,  protected  in  great 
measure  from  the  ocean.  At  the  bottom  of  this  shallow 
basin,  sandstone,  shale  and  limestone  were  formed.  The 
kind  of  rock  varied  with  different  sections  of  the  country 
and  periods  of  the  age,  according  to  the  peculiar  circum- 
stances which  influenced  the  deposit  of  sediment  at  any 
specified  place  or  time.  There  were  broad  areas  of  low 
mud-flats  and  wave-washed  sand  beaches.  There  may 
have  been  rivers  and  lakes  on  the  Azoic  continent,  but  if 
so,  they  have  entirely  disappeared  in  the  wreck  of  subse- 
quent changes.  The  land  was  rocky  and  barren,  while 
the  waters  swarmed  with  crustaceans  and  mollusks.  The 
pale  sun,  struggling  to  penetrate  the  dense  atmosphere  of 
a  yet  heated  primitive  world,  now  first  yielded  a  dim 
imperfect  light  to  these,  as  far  as  we  know,  earliest  cre- 
ated beings*  that  left  the  hand  of  the  Creator. 


*  We  have  already  spoken  of  the  EozoQn  of  the  Laurentian  rocks,  which,  if 
accepted  as  a  true  fossil,  is  the  oldest  known  inhabitant  of  our  globe.  Among 
the  Longmynd  rocks  of  Ireland,  Dr.  Oldham  discovered  a  zoQphite  (zo-o-Jite^ 
plant-animal,  a  class  of  polyps,  BO  named  because  they  resemble  both  plants  and 


THE     POTSDAM     PERIOD.  Ill 


POTSDAM     PERIOD. 

.  — This  period  is  named  from  Potsdam,  a 
town  in  northern  New  York,  where  the  rock  is  well  de- 
veloped. The  formation  is  very  thick  in  Pennsylvania, 
and  can  be  traced  westward  through  Michigan,  along  the 
southern  shore  of  Lake  Superior,  through  Wisconsin  and 
Minnesota  to  the  Black  Hills  of  Dacotah,  and  southward 
along  the  Appalachian  range  from  Vermont  to  Alabama. 
It  outcrops  at  many  other  places,  and  generally  underlies 
all  the  newer  sedimentary  rocks,  forming  over  the  entire 
continent  the  floor,  as  it  were,  on  which  the  more  recent 
deposits  rest. 

ICind  of  ffiocfc. — The  rock  varies  much  throughout 
this  wide  extent.  At  Potsdam  it  is  a  coarse,  hard  sand- 
stone ;  at  Malone,  N.  Y.,  a  friable  one ;  at  Keeseville,  a 
quartzite ;  and  at.  other  localities,  a  fine  white  sand,  fit 
for  glass-making.  At  some  points  east  it  is  a  good  build- 
ing-stone, while  at  the  west  it  is  often  so  friable  as  to 
crumble  in  the  fingers.  The  colors  are  brown,  gray,  yel- 
lowish, and  even  red.  In  many  localities  it  is  worm- 
burrowed,*  ripple-marked,  mud-cracked,  and  rain-pitted, 

animals),  which  in  his  honor  has  been  named  the  Oldhamia  antiqua.  These 
rocks  are  called  by  Sedgwick  and  Murchison  the  Cambrian.  The  latter  au- 
thority places  them  on  the  same  geologic  horizon  with  the  Huronian.  American 
geologists,  however,  believe  them  to  be  the  equivalent,  in  part,  of  Barrande's 
Primordial  Zone  of  Bohemia,  and  in  part  of  the  Potsdam  sandstone..  The  pupil 
will  see  from  this  that  the  question  of  the  "  dawn  of  life  "  on  our  globe  is  yet  an 
unsettled  one,  although  we  have  traced  it  back  to  where  organisms  of  the  lowest 
type  seem  to  just  emerge  out  of  the  igneous  rocks  of  the  primitive  earth.  * 

*  The  holes  burrowed  out  by  marine  worms  were  filled  with  sand,  which 
hardened  like  the  rock  itself,  and,  when  the  rock  is  broken,  form  regular  casts  of 
the  worm-burrow.  The  holes  are  like  those  now  made  along  the  eea-shore  iq 
the  same  way. 


112 


THE     SILURIAN    AGE. 


showing  the  mode  of  its  formation  on  a  low  sand-beach 
or  mud-flat.  The  upper  portion  of  this  period,  known  as 
the  Calciferous  Epoch,  is  in  part  calcareous,  so  that  some 
layers  are  even  burned  for  lime.  In  the  Mississippi  valley 
its  character  changes,  and  it  is  called  the  Lower  Magne- 
sian  Limestone.* 


FIG.  45. 


Lingula  antiqua. 

FIG.  46. 


A  Trilobite  (Dikelocephalus 
Minnesotensis). 


Fossils. — A  brachiopod,  the 
lingula  (little  tongue),  so  named 
from  its  peculiar  shape,  is  a  char- 
acteristic fossil.  The  form  and 
size  of  the  shell  are  similar  to 
that  of  the  finger-nail.  The  pecu- 
liarity of  this  mollusk  was  that, 
when  alive,  it  grew  on  a  fleshy 
stem  which  anchored  .it  to  the 
rock.  Several  species  of  the 
lingula  still  exist  in  the  Moluc- 
cas. A  crustacean,  the  triloUte 
(three-lobed),  is  the  most  con- 
spicuous fossil.  This  family  was 
prominent  in  the  early  creations, 
but  disappeared  in  the  Carboni- 
ferous Age.  It  is  perfectly  pre- 
served, and  the  various  stages  of 
growth,  from  the  egg  to  the  adult, 
have  been  more  accurately  traced 
than  even  those  of  the  crab,  a 


*  In  Wisconsin,  Iowa,  Minnesota,  and  Illinois,  this  is  overlaid  by  the  St. 
Peter's  sandstone,— a  soft,  white,  incoherent  rock,  composed  of  grains  of  quartz 
that  crumble  easily  under  the  hammer,  though  in  some  localities  it  is  hardened 
by  a  calcareous  cement.  It  is  used  in  Chicago  for  glass-making.  Like  tha 
Lower  Magnesian  Limestone,  it  is  destitute  of  fossils. — Whitney. 


THE     POTSDAM    PERIOD. 

living  crustacean.  It  was  of  wonderful  variety,  more 
than  400  species  having  been  discovered.  It  had  an 
oval  figure,  and  was  from  *  of  an  incli  to  24  inches  in 
length.  The  body,  divided  into  three  lobes,  was  covered 
with  small  plates  which  folded  over  each  other  as  in  the 
tail  of  the  lobster.  Some  species  could  roll  themselves 
up  into  a  ball,  and  thus,  present  a  hard  armor  in  every 
direction.  The  head  was  protected  by  a  buckler  of  a 
crescent  shape.  Its  eyes  were  very  curious.  They  were 
of  a  conical  shape,  and  each  one  was  composed  of  from 
40  to  6000  separate  facets  or  lenses,*  by  means  of  which 

FIG.  47. 


Eyes  of  Trilobites,  showing  that  the  eyes  of  insects  of  the  present  day  are  constructed 
on  the  same  plan.     3.  Enlarged  Lens. 


the  animal  could  see  in  every  direction  at  once.  The 
inner  side-"  of  each  eye  being  of  no  practical  value,  Na- 
ture, on  her  principle  of  economy,  placed  no  lenses 
there.  The  trilobite  is  supposed  to  have  gathered 
in  shoals  in  the  shallow  water,  swimming  slowly  on 
its  back  by  means  of  membranous  appendages  now 
lost. 


*  The  construction  of  the  eye  was  very  like  that  of  certain  insects  at  the 
present  day.  The  house-fly  has  14,000  of  these  facets,  the  butterfly  35,000,  and 
the  dragon-fly  00,000.  •  , 


114  THE     SILURIAN     AGE. 


S.  —  /.  The  Atmosphere.  —  The  eyes  of 
the  trilobite  would  have  been  useless  unless  the  atmos- 
phere had  been  clear  enough  to  permit  sufficient  sunlight; 
to  reach  the  earth  to  render  objects  visible  in  some  de- 
gree. God  makes  all  things  for  a  purpose  ;  hence  we  con- 
clude that  at  this  early  period  the  sun  had  pierced  tha 
clouds,  and  the  air  was  being  purified. 

2.  J?ar2y  Siltirian  3$eac?i.—  Where  the  Pots- 
dam rock  lies  on  the  surface,  we  are  assured  that  that 
locality  was  raised  above  the  sea  at  or  near  the  close  of 
this  period  (unless  uncovered  by  subsequent  denudation), 
else  it  would  have  been  concealed  by  the  sediment  of  the 
succeeding  one.  The  narrow  zone  of  the  Potsdam  rock 
along  the  borders  of  the  Azoic  area,  was  doubtless  the 
beach  of  the  early  Silurian  sea. 

J.  Z/ife.  —  The  organic  remains  found  in  this  period 
represent  the  Radiates,  Mollusks,  and  Articulates  among 
animals,  and  the  sea-weeds  among  plants.  The  trilobite 
was  the  highest  type.  Three  of  the  four  general  ideas 
of  expressing  animal  life  were  thus  simultaneously  de- 
veloped at  the  beginning;  the  fourth  does  not  appear 
until  long  after.  There  is,  says  Dana,  no  proof  that  the 
dry,  primordial  hills  bore  a  moss  or  lichen,  or  that  the 
ocean  contained  a  single  fish.  No  sounds  were  heard  in 
the  air  save  those  of  inanimate  Nature  —  the  moving 
waters,  the  tempest,  and  the  earthquake. 

^.  Climate.  —  No  difference  is  seen  in  the  life  of 
different  latitudes  ;  hence  it  is  thought  that  there  was  a 
uniformity  of  temperature  existing  over  the  earth,  and 


THE     POTSDAM    PERIOD.  115 

that  the  diversity  of  zone  and  climate  had  not  yet  been 
established.  Various  reasons  .have  been  assigned  for  this, 
among  which  are — (a)  the  greater  interior  heat  of  the 
earth  on  account  of  the  thinness  of  the  crust,  (b)  the 
dense  atmosphere  which  retained  the  sun's  heat  more 
fully,  (c)  the  great  expanse  of  the  ocean  which  tended  to 
equalize  the  temperature,  and  (d)  the  greater  size  and 
heat  of  the  sun  in  that  era,  according  to  the  nebular 
hypothesis. 

5.  Changes  in  the  Sea,  Z,ife,  and  fiocfc.— 

Shales  were  produced  in  the  muddy  water,  and  lime- 
stones in  the  shallow,  clearer  sea;  since  the  coral  animal 
tli  rives  best  in  pure  water  less  than  a  hundred  feet  deep. 
The  crust  of  the  still  unsteady  earth,  as  it  rose  and 
fell,  shallowing  or  deepening  the  waters,  rendering  them 
muddier  or  purer,  varied  the  character  of  the  life  sup- 
ported and  the  rock  formed.  There  were  frequent  tran- 
sitions of  this  kind  during  the  Potsdam  Period,  and 
especially  in  passing  into  the  Calciferous  Epoch,  when 
there  was  almost  a  complete  extermination  of  the  dif- 
ferent species. 

6.  £afce  Superior  ^Region. —  In  connection  with 
the  deposit  of  Potsdam  sandstone,  there  was  a  depression 
of  the   crust,  thus  forming  the  bed  of  Lake  Superior, 
and  also  igneous  ejections,  making  the  trap-rocks  and 
dikes  so  characteristic  of  that  section.     The  sandstone 
has  since  been  worn  into  grotesque   and  curious  forms 
as  seen  in  the  famous  Sculptured  and  Pillared  Rocks.* 


*  These  strata  form  a  wall  50  to  100  feet  high,  and  line  the  shore  for  a  distance 
of  five  miles.    Their  brilliant  hues  and  fantastic  shape  excite  the  imagination 


THE     SILURIAN-    AGE. 

7.  The  M'osaic  Account  fells  us  that  the  sun  and 
moon  were  created  on  the  fourth  day.  Geology  shows 
us  that  the  distinctive  feature  of  the  early  Silurian 
Age  was  the  partial  clearing  of  the  sky  after  the  murky 

FIG.  48. 


Sculptured  Rocks,  Lake  Superior.     "The  Inverted  Volcano." 

clouds  of  the  Azoic.  The  first  glimpse  of  the  sun  woulcf 
have  seemed  to  an  observer  as  a  new  creation,  and,  in 
•popular  language,  it  is  thus  described  in  Genesis.  "We 
also  read  that  on  the  fifth  day  the  waters  brought  forth 


of  every  beholder.  Here  is  "  Miner's  Castle,"  with  its  turrets  and  bastions ; 
there  "Sail  Rock,"  a  ship  with  sails  full  spread;  and  yonder  "The  Amphi- 
theatre," with  its  symmetrical  curves.  A  closer  inspection  only  reveals  more 
curious  details  and  resemblances.  For  a  very  interesting  account  of  these  rocks 
see  Harpers'  Magazine,  Vol.  XXXIV,  p.  681. 


THE     TRENTON    PERIOD.  Ill 

abundantly  the  moving  creature  that  hath  life.  We  shall 
see  how  perfectly  the  swarming  seas  of  the  Silurian  an<} 
Devonian  Ages  justify  this  description. 

t* 

TRENTON     PERIOD. 

^Location. — The  Trenton  formation  extends  along 
the  great  Appalachian  chain  of  mountains  on  the  east, 
thence  outcrops  at  various  points  westward  to  the  Missis- 
sippi river,  and  beyond  to  the  Rocky  Mountains.  It  is 
more  widely  distributed  than  any  similar  deposit. 

I£inds  of  2tock. — This  was  the  first  great  limestone 
period  of  the  continent.  In  New  York  there  are  four 
epochs — (l)  the  Chazy  limestone,  a  dark,  irregular  rock, 
named  from  a  locality  near  Lake  Champlain;  (2)  the 
Bird's  Eye  limestone,  a  dove-colored  rock  containing  fine 
white  crystalline  points  scattered  through  it;  (3)  the 
Black  River  limestone,  a  black,  hard-grained  marble 
capable  of  a  high  polish,*  named  from  the  river  of  that 
name,  east  of  Lake  Ontario;  (4)  the  Trenton  proper,  f  a 
hard,  compact  rock  of  a  grayish  or  black  color,  so  called 
from  the  well-known  gorge  at  Trenton  Falls.  This 
epoch  of  the  period  has  been  identified  in  Canada  and 
throughout  the  south  and  west,  but  the  other  epochs  vary 
somewhat,  and  their  equivalents  are  not  so  well  estab- 
lished. \ 


*  At  Watertown,  N.  Y.,  it  is  lumpy,  and  breaks  into  rhomboidal  fragments, 
while  the  Bird's  Eye  has  a  conchoidal  fracture.  Tli3  river  takes  its  name  from 
the  dark  color  of  the  rocks  over  which  it  flows. 

t  The  massive  pillars  of  the  court-house  at  St.  Louis  are  from  the  Trenton 
limestone  quarries  of  Sulphur  Spring.  The  crest  of  the  Falls  of  St.  Anthony  is 
of  Trenton  limestone.  In  Kentucky  and  Tennessee  this  rock  is  termed  tho 
atone  River  group. 


118 


THE      SILURIAN     AGE. 


(5)  In  Illinois,  Wisconsin,  and  Iowa,  the  Galena 
stone  overlies  the  Trenton.  It  is  the  great  lead  and  zinc 
bearing  rock  of  a  region  embracing  about  3,000  square 
miles.  The  streams  have  cut  deeply  down  into  this 
stone,  so  that  they  are  bordered  by  precipitous  bluffs 
crowned  by  perpendicular  ledges,  having  frequently  a 
castellated  appearance  like  the  walls  of  some  half-ruined 
city,  while  isolated  masses  sometimes  rise  abruptly  from 
the  valleys  like  lofty  watch-towers.  Dubuque  and  Ga- 
lena are  partly  situated  on  picturesque  bluffs  of  this  char- 
acter.* 


. — The  Chazy  limestone  is  not  characterized 
by  many  very  distinctive  fossils.  The  principal  ones  are 
gasteropods.  Fig.  49  represents  the  characteristic  marine 

FIG.  49. 


The  Bird's  Eye  Coral  (Phytopsis  tubulosum). 


*  The  QUEBEC  GROUP  is  thought  by  Hall  to  underlie  the  Chazy  (Sh£z-ee)  in 
New  York,  and  to  be  the  equivalent  of  Emnions1  much  disputed  TACOSUC  SY» 
T~3i.  Others  refer  both  to  the  Calciferous  epoch. 


THE     TRENT  OX     PERIOD.  110 

plant  which  is  found  in  the  Bird's  Eye  limestone.     The 
ends  of  the  stems  give  the  rock  the  dotted   appearance 
from  which  it  takes  its  name.     Fig.  59  gives  an  idea  of 
a  coral  common  in  the  Black  River  limestone.     It 
been  found  in  masses  of  a  ton's  weight.     The  Trenton 
limestone  abounds  in  organic 
remains.     The   flagstones  in 
the  streets  of  Ottawa  show 
branching   sea-weeds  spread 
out    on    their    surface ;    at 
Cincinnati,  where  the  rock 
is  known  as  the  Blue  lime- 
stone,   at    Nashville.   Tenn., 
and  at  many  other  widely-         Black  River  Coral  (Coiumnaria 
scattered     localities,    corals, 

crinoids,  and  shells  are  found  crowded  together  in  the 
greatest  profusion.  Thin,  semi-transparent  slices,  appa- 
rently devoid  of  fossils,  under  the  microscope  reveal  their 
animal  origin. 

Brachiopods  occur  in  wonderful  variety.  Trilobites, 
the  highest  type  of  the  Potsdam,  appear  of  a  dozen 
species,  varying  in  size  from  that  of  a  finger-nail  to  a 
foot  in  length.  They,  however,  now  yield  in  abundance, 
activity  and  power  to  the  cephalopods.  A  family  of  these, 
the  Ortlwceratite  (straight-horn),  distinguishes  the  entire 
period.  It  had  a  long  straight  shell,  divided  into  some- 
times as  many  as  seventy  chambers.  These  were  formed 
to  accommodate  the  growth  of  the  animal.  As  it  in- 
creased in  size,  it  moved  forward  in  its  room,  and  ex- 
tending its  shell  at  the  larger  end,  partitioned  off  its 
new  quarters  from  the  rest  by  a  shelly  wall.  Thus,  in 
time,  a  long  series  of  chambers  were  made,  each  larger 


120  THE     SILURIAN    AGE. 

than  its  predecessor.*  They  were  connected,  however, 
by  a  membranous  tube  ("  siphuncle  "),  which  passed 
from  the  animal  in  the  newest  and  largest  chamber  at 
one  end  to  the  oldest  and  smallest  room  at  the  other. 
These  empty  chambers  are  thought  to  have  acted  as 
a  buoy  to  float  the  heavy  animal.  Some  of  the  fossil 
orthoceratites  are  not  larger  than  a  lead  pencil,  while 
others  are  a  foot  thick  and  thirty  feet  in  length.  They 
had  many  muscular  arms,  with  which  they  seized  and 
strangled  their  prey  in  their  powerful  grasp.  They  were 
doubtless  the  sea-rovers  of  the  Lower  Silurian  Ocean. 


.—  /.  Z<ife  and  tDeath  were  coeval  from 
the  first  —  one  species  giving  place  to  another,  most  com- 
monly at  the  close  of  a  period,  but  frequently  within 
its  duration.  After  the  exterminations  of  the  last  period. 


"  Year  after  year  beheld  the  silent  toil 

That  spread  his  lustrous  coil ; 

Still  as  the  spiral  grew, 
He  left  the  past  year's  dwelling  for  the  new. 
Stole  with  soft  step  its  shining  archway  through, 

Built  up  its  idle  door, 
Stretched  in  his  last-found  home,  and  knew  the  old  no  more. 

*  Thanks  for  the  heavenly  message  brought  by  thee, 

Child  of  the  wandering  sea, 

Cast  from  her  lap  forlorn. 
Cast  from  thy  dead  lips,  a  clearer  note  is  born 
Than  ever  Triton  blew  from  wreathed  horn  ; 

While  on  my  ear  it  rings, 
Through  the  deep  caves  of  thought,  I  hear  a  voice  that  singe : 

14  'Build  thee  more  stately  mansions,  oh,  my  soul, 
As  the  swift  seasons  roll ! 
Leave  thy  low-vaulted  past ! 
Let  each  new  temple,  nobler  than  the  last, 
Shut  thee  from  heaven  with  a  dome  more  vast 

Till  thou  at  length  art  free  ; 
Leaving  thine  outgrown  shell  by  Ufa's  unresting  aea.*** 


TRILOBITES   OF   TRENTON    PERIOD. 


FIG.  51. 


i.  Asaphus  (Isotelus)  gigas. 


2.  Illaenus  trentonensis. 


Orthoceras  multicameratum  (Black  River  Epoch). 


122  THE     SILURIAN    AGE. 

the  sea  was  repopulated  by  new  species,  but  of  the  old  gen- 
era represented  in  the  Potsdam.  It  was  still,  however,  the 
reign  of  mollusks,  since  that  sub-kingdom  was  exhibited 
in  its  various  classes,  while  the  articulates  had  not  pro- 
gressed above  the  crustaceans  and  worms,  and  no  verte- 
brates have  been  discovered  as  yet.  No  terrestrial  species 
of  any  kind  have  been  found.  The  only  plants  yet 
known  were  sea-weeds.  The  land,  so  far  as  geology 
teaches,  remained  leafless  and  lifeless  as  at  the  beginning. 
The  sea,  however,  in  its  shallower  places,  resembled  a 
flower-garden,  with  its  abundant  corals. 

2.  Geograpfi/y.  —  The  Green  Mountains  were  ele- 
vated above  the  sea,  though  not  to  their  full  height, 
about  the  close  of  this  period.  We  know  this  because 
their  tops  contain  Trenton,  but  no  Hudson  Eiver  rocks. 

HUDSON    PERIOD. 

£ocation  .  —  This  formation  is  exposed  to  view  along 
the  Mohawk  river,  N.  Y.,  on  the  shores  of  Lake  Huron, 
and  in  many  of  the  western  and  southern  States  ;  also 
along  the  Appalachian  range  to  Alabama.  From  its 
abundance  near  that  city,  it  has  also  received  the  name 
of  the  "  Cincinnati  Limestone." 


J&nds  of  ffocfc.*—Ii  consists  mainly  of  soft  clay  or 
shales,  and  even  the  Cincinnati  limestone  is  interlami- 
nated  with  shale  or  marl.  Its  color  is  dark,  and  it  is 
frequently  bituminous,  so  as  to  afford  a  black  pigment. 
There  are  thin  seams  of  coal  which  have  many  times 
tantalized  those  ignorant  of  geology  with  unfounded 
hopes  of  the  discovery  of  profitable  beds  of  coal. 


THE     HUDSON    PERIOD.  123 

ils. — In  the  limestone  regions  corals,  shells,  tri- 
lobites,  etc.,  are  abundant  as  in  the  Trenton  Period.  In 
the  shales,  however,  they  are  sparingly  distributed,  being 
mostly  those  which  nourish  in  muddy  waters.  The 
graptolites  (rock-writing)  of  the  kingdom  of  Radiates 
are  striking  fossils  (see  Fig.  53).  They  are  found  in  the 
Potsdam,  but  become  very  plentiful  in  the  Hudson 
Period.  They  are  merely  a  delicate,  plume-like  tracery 
upon  the  rock.  They  have  been  therefore  poetically 
styled  sea-pens.  They  delighted  in  foul,  as  the  corals  in 
clear  water,  and  must  have  thickly  covered  the  muddy 
bottom  of  the  shallow  sea  with  their  fragile,  mossy 
branches.  They  are  found  commonly  in  scattered  frag- 
ments, the  arms  only  of  the  entire  animal  as  seen  in 
Fig.  53.  '  M- 


A  Graptolite  with  Eight  Arms  (Graptolitluts  octobrachiatus). 


.—  G-eograpJiy  .  —  The  River  St.  Lawrence 
was  fast  assuming  its  present  proportions.  Lake  Cham- 
plain  and  Hudson  River  probably  date  from  this  time. 
The  continent  was  steadily  pushing  its  way  south- 
ward, and  had  reached  the  central  part  of  New  York, 


124  THE     SIL  US  I A  N    A  G  E. 

western  Vermont  had  emerged  from  the  sea,  while  the 
then  low,  narrow  Eocky  Mountains  represented  the  west- 
ern part  of  the  continent. 

N  IAGARA    PERIOD. 

Jsocation. — This  is  a  widespread  formation  like  the 
Trenton.  It  is  found  in  Canada,  south  through  the 
Appalachian  region,  and  west  through  the  Mississippi 
valley.  It  takes  its  name  from  the  fact  that  the  great 
cataract  of  Niagara  pours  over  a  rocky  wall  of  this  period. 
The  peculiar  form  of  the  fall  is  owing  to  the  fact  that  the 
soft  shale  below  wears  away  -more  rapidly  than  the  hard 
rock  above,  thus  leaving  a  cavern  behind  the  falling 
sheet. 

l&nds  of  Ztocfc. — In  New  York  there  are  four 
epochs  of  this  period. 

1.  THE  OKEIDA  GROUP,  called  from  a  county  of  that 
name  in  central   New  York,  is  a  gritty,  hard   rock,   so 
rough  as  to  form  millstones. 

2.  THE   MEDINA  GROUP,  named  from  the  locality  in 
western  New  York  where  the  rock  is  extensively  quar- 
ried for  building  purposes,  is  a  thickly  laminated  sand- 
stone, of  red,  gray,  and  beautifully  mottled  colors. 

3.  THE  CLINTOK  GROUP,  so  called  from  a  village  in 
central  New  York,  is  a  shaly  sandstone.* 

4.  THE  NIAGARA  proper  is  a  limestone  of  a  light  gray 


*  In  Michigan  and  some  of  the  western  States  it  assumes  more  of  a  limestone 
character,  and  in  New  York,  Ohio,  and  Wisconsin,  has  beds  of  oolitic  iron  ore  of 
great  value.  In  Tennessee  it  is  called  "  dye-stone,11  being  extensively  used  for 
dyeing  cloth, 


THE     NIAGARA     PERIOD  125 

or  cream  color,  and  of  an  enduring  hardness,  but  yet  soft 
enough  to  be  easily  wrought  to  any  desired  form.  At 
Chicago  it  is  called  the  "  Athens  marble,"  and  is  almost  a 
pure  dolomite.  At  Lockport,  New  York,  dog-tooth  and 
pearl-spar,  also  gypsum  and  other  minerals,  are  found  in 
beautiful  crystals  lining  the  cavities  in  the  rock.  At  the 
west  the  Niagara  limestone  —  including  also  the  Helder- 
berg  —  stands  in  bold  bluffs  along  the  river  banks.  It 
contains  nodules  of  horn  stone  ("  chert  "),  often  arranged 
in  layers  parallel  to  the  strata.  The  Niagara  rock  is  fre- 
quently found  capping  small  hills  or  knobs,  and  has 
hence  received  the  name  "Mound  limestone."* 


.  —  In  the  Clinton  beds  a  brachiopod  (the 
pentamerus,  five-parted)  is  very  abundant.  This  is  pecu- 
liarly interesting  because  it  is  known  to  be  spread  in 
strata  of  this  period  from  Europe  to  the  west  of  the 
Mississippi.  Sea-weeds  (fucoids)  cover  the  Medina  sand- 
stone in  many  places  with  their  interlacing  stems,  curi- 
ously wrought,  like  the  intricate  carving  of  some  old 
Gothic  cornice.  The  Niagara  rocks  abound  in  corals, 
crinoids,  shells,  etc.  They  are  doubtless  the  remains  of 
old  coral  reefs. 

The  crinoids  appeared  in  preceding  periods,  but  now 
became  very  plentiful.  They  grew  on  a  stem,  and  had 
somewhat  the  form  of  a  lily,  hence  have  received  the 


*  The  Blue  Mounds,  the  Platte  Mounds,  Sinsinnewa  Mound,  in  Wisconsin ; 
Sherald's,  in  Iowa  ;  Scales's,  Charles's,  Waddell's,  Pilot's  Knob,  etc.,  in  Illinois, 
are  striking  examples  of  this  peculiarity,  since  they  form  conspicuous  landmarks 
in  the  scenery  of  those  States.  These  outliers  of  the  Niagara  limestone  assume  a 
great  variety  of  forms,  but  are  always  graceful  in-their  outlines,  and,  aa  they  are 
generally  covered  with  forest  trees,  present  a  striking  contrast  to  the  rocky 
bluffs  of  the  Galena  limestone. 


126 


THE     SILURIAN     AGE. 


name  of  "  stone-lilies."     Their  cup-shaped  body  sent  out, 
star-like,  five  arms;   these  branched  sometimes  into  as 

FIG.  55. 


Medina  Fucoid  (Arthrophycus  Harlani.) 


many  as  a  thousand,  each  composed  of  a  hundred  little 
bones,  firmly  and  exquisitely  jointed  together.  The  stalk 
was  also  jointed,  like  the  vertebrae  of  the  spine,  and  was 
curiously  grooved  and  ornamented  on  the  surface.  The 
arms  were  adapted  to  be  spread  out,  and  to  seize  and 
draw  into  the  centre  shoals  of  animals,  the  food  of  the 
crinoid.  In  many  places  the  rock  is  a  confused  mass 
of  crinoidal  stems  (Figs.  58  and  75). 


THE     NIAGARA     PERIOD.  127 

FIG.  56. 


A  Niagara  Coral. 

. —  The  Appalachian  region  does  not  seem  to 
have  received  any  Niagara  deposits  from  the  clear  sea 
which  covered  the  central  part  of  the  continent  and  pro- 
duced limestones.  It  appears  rather  to  have  been  a  reef 
bordering  the  Atlantic  Ocean,  from  which  mud  and  clay 
were  constantly  washed  in  great  quantities.  Under  its 
lee  the  interior  sea  protected  the  corals,  mollusks,  and 
crinoids  that  during  the  great  limestone  periods  swarmed 
in  the  clear  shallow  waters. 


SALINA    PERIOD. 

^Location . — The  Salina  period  is  named  from  the 
salt  springs  near  Syracuse,  N.  Y.  The  rock  occurs  in 
Michigan,  and  perhaps  at  the  west  and  south. 


NIAGARA    CRINOIDS. 

FIG.  57 


Ichthyocrinus  laevis. 


Lecanocrinus  macropetalus, 


THE     SAL  IN  A     PERIOD. 


Fragment  of  Encrinital  Limestone,  Niagara  Period. 

of  32oc£.—ThQ  rocks  consist  mainly  of 
shales,  marls,  and  some  limestone.  The  saliferous  beds  are 
about  1,000  feet  in  thickness,  showing  a  long  continuance 
of  the  peculiar  conditions  under  which  they  were  formed. 

Fossils.—  It  seems  nearly  destitute  of  fossils.  The 
conditions  of-  the  water,  sometimes  too  salt  for  any  life, 
and  sometimes  too  fresh  for  marine  life,  were  unfavorable 
for  the  existence  of  animals. 


.—  /.  The  Salt  Springs  of  Syracuse  have 
been  accounted  for  in  the  following  manner:  Central 
New  York  is  considered  to  have  been  at  that  time  a 
great  salt  lake,  shut  off  mainly  from  the  sea.  By  con- 
tinued evaporation,  by  fresh  overflows  of  the  brine  from 
the  ocean,  and  by  washings  of  rains  and  streams  from  the 
adjacent  land,  muddy  deposits  were  formed,  thoroughly 
impregnated  with  salt. 

2.    Gypsum  abounds  in  many  localities.    It  seems  to 
have  been  formed  after  the  limestone  was  deposited,  since 


130  THE     SILURIAN    AGE. 

in  places  where  the  gypsum  has  been  dug  out,  well-like 
holes,  passing  through  continuous  strata  of  limestone, 
have  been  left.  The  process  appears  to  have  been  as 
follows  :  Sulphur  springs  produce  sulphuric  acid  by  oxy- 
dation  from  the  air.  This  acid  acting  on  the  carbonate 
of  lime,  converts  it  into  the  sulphate  of  lime  (gypsum). 
Sulphur  springs  still  abound  in  this  group,  and  there 
is  a  very  celebrated  sulphuric  acid  spring  near  Alabama, 
Genesee  county,  N.  Y.  ;  lience  it  is  probable  that  gypsum 
is  still  in  process  of  formation. 

LOWER    HELDERBERG     PERIOD. 


.  —  This  period  takes  its  name  from  the 
Helderberg  Mountains,  near  Albany,  "N.  Y.  The  rocks 
gradually  disappear  in  the  western  part  of  the  State,  but 
are  conspicuous  southward  along  the  Appalachian  range, 
and  reappear  in  Maine,  and  also  in  Illinois  and  Missouri. 

ICind  of  Itock.  —  This  is  also  a  great  limestone 
formation,  but  differs  from  the  Trenton  and  Niagara 
groups  in  being  thickest  on  the  eastern  border.  The 
lower  beds  in  New  York  and  Virginia  are  used  for 
hydraulic  cement,  whence  their  name  —  the  "Water-lime 
group." 

Fossils.  —  The  conditions  of  life  seem  to  have  been 
eminently  favorable.  About  four  hundred  species  of  ani- 
mals have  been  discovered.  A  brachiopod  (Pentamerus 
galeatus)  is  so  common  in  some  sections  as  to  give  its  name 
to  the  rock.  A  peculiar  crustacean,  the  eurypterus  (broad- 
fin),  is  allied  to  the  trilobite.  Crab-like  in  its  organs  of 


LOWER     HELDERBERG     PERIOD. 


131 


mastication,  lobster-like  in  its  prolonged  and  segmented 
body,  with  its  broad  swimming-limbs  and  huge  claws, 


FIG.  59. 


Pentamerus  galeatus. 


Eurypterus  remipes. 


FIG.  61. 


it  presents  a  new  and  striking  family.     Some   seem  to 

have  been   six  or  eight  feet  in  length. 

.They  were  the  scavengers  of  their  time, 

living  on  the  lower  forms  and  garbage  by 

the  sea-shore.     Small,  cones,  called  Ten- 

taculites,  are  so  abundant  in  some  places 

as  to  COmpOSe  the  maSS  Of  the  rOCk.  Tentaculites  ornatus. 


.— /.  Geograp?i/y.—  The  formation  of  lime- 
stone in  this  period  in  eastern  New  York  and  in  the 
Green  Mountain  region  shows  that  these  sections  must 
have  been  depressed,  and  the  mountains,  in  part  at  least, 
again  submerged  in  the  sea.  More  than  half  of  New 
York,  nearly  all  of  Canada  and  Wisconsin,  had  now 
become  dry  land.  A  great  bay,  however,  covered  a  large 
part  of  Michigan.  The  rivers  were  probably  small,  and 
fresh  water  lakes,  if  any  existed,  have  disappeared. 


THE     SILURIAN    AGE. 

2.  Climate.  —  The  fossils,  constituting  a  kind  of 
life-  thermometer,  indicate  that  the  climate  of  the  Silurian 
was  uniform. 


3.  ^Progress  of  _Z^y<?.—  The  grand  types  of  life 
remain.  Continued  changes,  however,  take  place  in  the 
development  of  the  creative  idea  by  the  disappearance* 
of  old  genera  and  the  appearance  of  new  ones.  Mollusks 
continue  to  take  the  lead,  while  the  articulates  are  rep- 
resented as  yet  only  by  the  second  class  —  crustaceans. 
Neither  plant  nor  animal  is  seen  on  the  land,  and  no 
fishes  sport  in  the  waters. 

^  .  Uniformity  of  Nature.  —The  construction  of 
the  eyes  of  the  trilobite  shows  that  the  laws  of  light  were 
the  same  then  as  now.  The  animal  itself  was  very  like 
the  king-crab  of  the  Atlantic  coast.  The  orthoceratites 
were  the  progenitors  of  the  nautilus,  the  shell  being  un- 
coiled in  those  early  species.  The  sea-shore  was  clad 
in  weeds,  and  in  favorable  localities  the  waters  were 
thronged  with  inhabitants.  Species  and  genera  took 
their  places  in  the  grand  sub-kingdoms  of  animal  life. 
It  requires  no  great  stretch  of  the  fancy  to  people  those 
early  seas,  and  imagine  them  busy  and  joyous  on  a  sum- 
mer's eve  as  the  tribes  that  throng  our  existing  oceans. 

/     SCENIC  DESCRIPTION.-!**  us  picture  to  our- 
selves the  scenery  of  the  Silurian  Age.     The  air,  damp 


*  For  example,  the  chain-coral  and  graptolites  passed  away  with  the  Upper 
Silurian,  while  the  crinoids  greatly  increased.  Dana  says  that  not  one  species 
belonging  to  the  latter  part  of  the  .Lower  Silurian  existed  at  the  close  of  the 
Upper  Silurian. 


THE     SIL  UR1 A  N    AGE.  133 

with  fogs  and  foul  with  noxious  gases,  hangs  heavy  over 
land  and  sea.  The  sun  sheds  a  strange  lurid  glare.  The 
land,  faintly  visible  in  the  dim  light,  presents  few  attrac- 
tions. The  new-born  continent  is  yet  crude  and  unfin- 
ished. Vapor  is  rising  in  clouds  from  the  heated  surface. 
With  no  song  of  bird,  nor  hum  of  insect,  nor  garment  of 
verdure,  it  is  a  broad,  low,  barren,  rocky  desert.  Every- 
where are  seams,  and  gulfs,  and  ridges,  rent  and  upheaved 
by  earthquake  shocks,  and  swept  by  volcanic  floods.  The 
sea  is  the  only  centre  of  life.  The  low  rocky  beach 
is  garnished  with  innumerable  sea-weeds,  whose  long 
trailing  branches  rise  and  fall  with  the  tide,  while  every 
wave  strews  the  sand  with  shells  and  broken*  corals, 
heaped  in  lengthened  rows  like  the  grass  from  the  mow- 
er's scythe.  Trilobites,  in  swarming  shoals,  scull  their 
tiny  boats  in  animated  pursuit  of  food.  Huge  orthocera- 
tites  lie  quietly  floating  their  many-chambered  shells  on 
the  surface,  or  speed  through  the  water  with  long  arms 
spread  to  grasp  their  prey.  The  sea-bottom  is  gay  with 
the  lily-shaped  crinoids  that,  blossoming  with  life,  fore- 
shadow the  flowers  which  are  yet  to  deck  the  barren 
earth.  Coral  reefs  stretch  away  in  lines  of  beauty,  where 
myriad  workers  toil  to  build  their  many-colored  fragile 
homes.  In  shallower  places,  too,  there  is  somewhat  of 
grace,  for  the  graptolites  cover  the  muddy  bottom  with 
their  quaint  mossy  branches,  overshadowing  mollusks 
that  sluggishly  luxuriate  in  endless  profusion  below.  Yet 
as  the  long  age  goes  by,  continued  changes  take  place. 
The  land  rises  and  falls.  The  sea  retires,  and  anon  pours 
swelling  in  again.  The  scene  of  life  shifts  from  one 
locality  to  another.  The  great  drama  of  life  and  death 
has  begun,  and  is  to  be  played  while  the  earth  endures. 


J34  fSE     DEVONIAN    AGE. 


II.   THE    DEVONIAN    AGE. 

i.  Oriskany  Period. 

,   2.  Corniferous  Period. 
THE  DEVPNIAN  AGE.  -!  ^  Hamilton  Period 

4.  Chemung  Period. 

This  second  great  stage  in  the  progress  of  life  on  the 
earth  takes  its  name  from  the  county  of  Devon,  England, 
where  the  formation  is  very  clearly  and  extensively  de- 
veloped.* It  is  often  styled  the  OLD  BED  SANDSTONE, 
from  the  prevalent  color  of  the  rock,  and  has  been  im- 
mortalized by  Hugh  Miller  under  that  name.  On  this 
continent  its  color  and  character  are  very  different, 
although  it  is  similar  in  its  dominant  fossils. 

General  Characteristics. — The  continent  is  still 
small,  low,  and  rocky.  The  Silurian  sea  is  gradually 
retiring  southward,  as  period  after  period  adds  its  belt  to 
the  growing  margin  of  the  land.  The  earth,  however,  is 
no  longer  lifeless.  Flags  and  rushes  abound  by  the 
water-courses,  while  ferns  of  rare  beauty  and  plants  very 
like  our  rushes,  flourish  in  the  marshes.  There  are  some 
cone-bearing  trees,  but  no  flowering  tree  or  shrub  like 
the  maple,  elm,  or  rose.  The  graptolites  have  become 
extinct,  the  trilobites  are  reduced  to  about  a  dozen 
species,,  while  that  curious  crustacean,  the  eurypterus, 
appears  in  profusion  in  Europe,  but  rarely  in  America. 

The  most  marked  feature  is  the  fishes  which  swarm  in 


FISHES     OF    DEVONIAN    AGE.  135 

the  seas.*  They  were  nearly  all  Ganoids,  i.  e.,  they  had 
beautifully  enameled  scales  encasing  them  as  with  an 
armor,  and  often  a  bony  helmet  large  enough  to  cover 
the  skull  of  an  elephant,  strong  enough  to  resist  a 
musket-ball,  and  hard  enough  to  strike  fire  like  a  flint. 
The  tail  was  nearly  always  of  unequal  lobes,  instead  of 
equal  lobes  or  rounded  forms,  as  at  the  presen-t.  Thus, 
says  Agassiz,  the  progress  of  life  through  the  ages  has 

FIG.  61. 


t.  Heterocercal,  or  Unequally  bilobate ;    2.   Equally  bilobate ;    and,   3.    Single  and 
rounded  form  of  tail. 

been  marked  in  the  tails  of  the  fishes.     Among  the  most 
peculiar  of  these  fishes  we  notice — 

1.  THE    COCCOSTEUS    (berry-bone),   which    takes    its 
name  from  the  tiny  berry :like  projections  ornamenting 
its  plated  armor.     Its  teeth  are  chiseled,  as  it  were,  out 
of  the  solid  jaw,  just  as  the  teeth  of  a  saw  are  cut  out  of 
the  solid  metal. 

2.  THE    PTEKICHTHYS   (wing-fish)   had  two  arms  or 
wings,  combining  the  broad  blade  of  a  paddle  with  the 


*  Anderson  says  the  remains  of  these  Ganoid  fishes  are  so  abundant  in  the 
yellow  sandstone  deposit  of  Dura  Den,  Scotland,  that  a  space  of  little  more  than 
three  square  yards  yielded  above  1,000  fishes,  most  of  them  perfect  in  their  out- 
line, with  scales  and  fins  quite  entire,  and  the  forms  of  the  creatures  often  start- 
ing freely  out  of  their  hard,  stony  matrix  into  their  complete  armature  of  ecale, 
fin  and  bone. 


186 


THE      DEVONIAN      AGE, 


FlG.  62. 


Fishes  of  Devonian  Sea.     i.  Coccosteus.     2.  Pterichthys.     3.  Cephalaspis.    4.  Holop- 
tychius.     5.  Osteolepis. 


FISHES    OF   DEVONIAN   AGE.  187 

eharp  point  of  a'  spear,  which  served  both  for  propul- 
sion and  for  offence.  The  head  was  covered  with  a 
strong  helmet,  perforated  in  front  by  two  circular  holes, 
through  which  the  eyes  looked  out.  Its  chest  was  pro- 
tected by  a  curiously  constructed  cuirass  formed  of 
plates,  and  the  tail  was  sheathed  in  a  flexible  mail  of 
bony  scales. 

3.  THE  CEPHALASPIS  (buckler-head)  had  a  head-plate 
of  a  single  bone  of  a  crescent  shape. 

4.  THE  HOLOPTYCHIUS  (all- wrinkled)  is  so  called  from 
the  curiously  wrinkled    sculpturing    that    adorned    its 
scales. 

5.  THE  OSTEOLEPIS  (bony-scale),  whose  bony  scales  are 
placed  alongside  each  other  like  the  bricks  in  a  building, 
thus  affording  protection,  and  at  the  same  time  yielding 
readily  to  the  bending  of  the  body. 

Jn  these  fishes  there  is  a  singular  union  of  reptilian 
and  fishy  traits.  The  structure  of  their  skull  resembled 
that  in  reptiles,  while  their  air-bladders  had  a  lung-like 
character.  They  could  move  the  head  upon  the  neck 
independently  of  the  body.  Like  reptiles,  also,  their 
vertebrae  were  connected  by  ball  and  socket  joints  in- 
stead of  inverted  cones,  as  in  common  fishes. 

V  Comprehensive  Types.  —  The  Creative  purpose 
seemed  at  the  beginning  to  be  sketched  in  broad,  gen- 
eral characters,  and  to  include  in  the  first  expression  of 
the  plan  all  the  structural  possibilities.  This  combina- 
tion of  higher  with  lower  features  in  the  early  organic 
forms  is  a  very  striking  peculiarity,  and  becomes  still 
more  significant  when  we  notice  that  many  of  the  later 
types  recall  the  more  ancient  ones.  The  latter  may  be 


138  THE    DEVONIAN    AGE. 

styled  prophetic  'and  the  former  retrospective  types,  since 
the  one  anticipates  the  future  and  the  other  recalls  the 
past.  The  crinoids,  with  closed  cups  in  some,  and  open, 
star-like  forms  in  others,  united  features  of  the  present 
star-fishes  and  sea-urchins,  and  by  their  stems,  which 
fastened  them  to  the  ground,  included  also  a  polyp-like 
character.  The  armor-plated  pterichthys  propelled  itself 
with  paddle-arms,  like  the  turtle,  instead  of  with  the 
tail,  like  other  fishes.  Th'e  trilobites,  with  their  uniform 
rings  and  head-shield,  partook  at  once  of  worm  and 
crustacean  types.  The  chambered  shells  of  the  ortho- 
ceratite  and  goniatite  gave  hints  of  the  ammonite  of  a 
later  age.  The  early  fishes  prophesied  not  only  the  rep- 
tiles which  were  to  come,  but  also  the  birds  and  even 
mammals.  Though  the  ancient  types  have  become  obso- 
lete and  have  been  replaced  by  modern  ones,  as  Agassiz 
happily  remarks,  a  few  old-fashioned  individuals  have 
been  left  behind  to  give,  as  it  were,  the  key  to  the  history 
of  the  race.  The  gar-pike  explains  the  ancient  Devonian 
fishes;  the  Millepore  coral,  the  old  Silurian  corals;  the 
nautilus,  the  ammonite  and  orthoceratite.  The  thought 
of  God  thus  includes  all  that  have  gone  before  as  well  as 
all  that  now  exist.  The  study  of  nature  reveals  to  us  the 
present  linked  with  the  past,  which  is  not  lost  and  dead, 
but  perpetually  revivified  and  reproduced  in  the  life  of 
to-day. 


THE    ORISKANY   PERIOD.  139 


ORISKANY    PERIOD.* 

ZtOCdlion.  —  This  formation  is  named  from  Oris- 
kany  Falls.  The  rock  crops  out  at  points  in  Maine,  and 
extends  southward  along  the  Appalachian  region. 


J£ind  of  jRocfc.  —  It  is  mostly  a  light,  rough  sand- 
stone. Its  thickness  in  New  York  varies  from  twenty 
feet  at  the  typical  locality  to  only  a  few  inches  at  other 
places  ;  in  Pennsylvania  it  is  200  feet  thick.  Its  color  is 
white,  passing  to  a  reddish-brown  where  iron  is  present. 

Fossils.  —  The  most  common  fossil  is  a  brachiopod 
(Fig.  63).  The  rock  is  often  made  up  of  these  charac- 


FIG.  63. 


Spirifer  arenosus. 


*  In  Southern  Illinois  there  is  a  formation  termed  the  Clear  Creek  limestone, 
which  seems  to  mark  a  transition  from  the  Silurian  to  the  Devonian,  since  it 
contains  well-marked  fossils  of  both  ages.  It  forms  the  Mississippi  Bluffs  south 
of  Thebes. 


HO  THE    DEVONIAN   AGE. 

teristic  shells  or  of  thin  casts.     The  latter  are  represented 
in  Fig.  64.    It  is  a  mould  of  the  interior  of  the  shell 


FIG.  64. 


formed  TJJ  the  eani  -which  filled  it,  while  the  substance 
of  the  shell  itself  has  decomposed.  These  casts  are 
very  abundant,  as  in  Cumberland,  Md.,  and  have  re- 
ceived many  fanciful  names,  such  as  "colts'  tracks," 
"butterflies,"  etc, 


i.—  This  formation  [3  another  feature  of  the  old 
Appalachian  sea-beach.  The  (-h\^kness  of  the  rock,  as  it 
extends  southward  from  the  Azoic  area,  indicates  a 
deepening  of  the  water  which  covered  both  New  York 
and  New  England.,  while  the  Gr^en  Mountains  were  a 
narrow  island  separating  them. 


*  The  material  for  making  thevcontinent  carrm  always  from  the  north-east. 
For  this  reason  formations  are  generally  coarser  east,  and  finer  west.  Shales 
and  sandstones  east  often  become  limestones  wtsvu 


UP  P  Eli     HELD  ERE  ERG     PERIOD.  11+1 


UPPER    HELDERBERG    OR    CORNIFEROUS 
PERIOD. 

Jjocation. — The  lower  group  is  found  in  New  York, 
and  somewhat  in  New  Jersey  and  Pennsylvania ;  the 
upper  group  is  widely  distributed  through  the  interior  to 
the  States  beyond  the  Mississippi.  At  the  west,  owing  to 
the  absence  of  the  Oriskany,  the  Corniferous  rocks  lie 
directly  upon  the  Niagara  limestone,  except  where  the 
Salina  intervenes. 

J^inds  of  ffiock.  —  This  formation  in  New  York 
comprises  two  epochs : 

1.  THE  CAUDA  GALLI  A:NT>  SCHOHAEIE  GRITS,  which 
are  named — the  former  from  a  peculiar  feathery  sea-weed 
common  in  it,  and  the  latter  from  the  typical  locality  in 
eastern  New  York. 

2.  THE  HELDERBERG  LIMESTONE — the  last  great  lime- 
stone formation  in  New  York — the  lower  beds  of  which 
are  termed  the  Onondaga}  and  the  upper  the  Corniferous 
limestone. 

The  Helderberg  beds  lose  their  distinctive  features 
westward  and  blend  into  one  group,  which  is  called  by 
either  of  these  names.  The  Corniferous  limestone  (cornu, 
a  horn)  derives  its  appellation  from  disseminated  nodules 
of  hornstone  ("chert").  The  Onondaga  is  a  dark-gray 
rock  which  takes  an  excellent  polish.  These  limestones 
are  quarried  as  a  building-stone  at  multitudes  of  points 
throughout  western  New  York,  Ohio,  Michigan,  Indiana, 
Illinois,  and  Iowa. 


142  THE    DEVONIAN   AGE. 

Fossils.  —  This  was  the  great  Palaeozoic  coral  reef. 
Corals  are  found  in  every  conceivable  form — standing, 
lying  down,  broken  into  fragments,  or  preserved  as 
perfectly  as  if  they  had  grown  but  yesterday.  They 
nourished  luxuriantly  and  may  have  exhibited  all  the 
wealth  of-  coloring  now  manifested  in  the  tropical  seas. 
They  are  especially  abundant  at  the  Falls  of  the  Ohio, 
near  Louisville.  Some  have  a  diameter  of  five  or  six  feet. 
Crinoids  and  mollusks,  in  all  their  orders,  present  a  be- 
wildering variety  and  profusion. 


HAMILTON       PERIOD. 

Z/ocalion .  —  This  formation  extends  across  ISTew 
York,  Michigan,  thence  west  of  the  Mississippi  river, 
and  southward  through  Pennsylvania,  Virginia,  and 
Tennessee. 

ICinds  of  ffiock.  —  In  New  York  this  period  com- 
prises three  epochs.* 


*  The  entire  Hamilton  series  in  New  York  makes  one  enormous  formation, 
the  strata  being  in  all  5,000  or  more  feet  in  thickness.  They  are  nearly 
destitute  of  lime,  and  thus  differ  widely  from  the  Onondaga,  Trenton,  and 
Niagara  limestones  which  overlie  them  on  the  north.  They  give  rise  to  marked 
peculiarities  in  the  country  which  they  underlie,  and  also  affect  its  soil  and  pro- 
ductions. Containing  little  lime,  we  find  the  culture  of  wheat  does  not  gener- 
ally succeed  well  upon  them ;  nor  does  the  central  wheat-growing  district  ex- 
tend upon  them  more  than  a  few  miles  south  of  the  limestone  range,  except  in 
a  few  alluvial  valleys,  or  places  where  calcareous  materials  from  the  limestone 
belts  have  been  strewed  over  the  southern  slates  by  the  Drift,  of  which  we 
shall  speak  hereafter.  Grazing  and  dairying  are  almost  exclusively  the  pursuits 
of  the  farmer. 

The  most  marked  physical  features  of  all  this  great  extent  of  country  consist 
in  its  deep  valleys  and  long  ridgy  hills,  usually  extending  in  a  north  and  south 
direction,  as  an  inspection  on  any  map  of  the  rivers  which  follow  the  valleys 
will  show.  Some  of  these  long  north  and  south  valleys  having  been  excavated 


THE      HAMILTON     PERIOD.  1J+1 

1.  THE  MARCELLUS  SHALE  is  a  soft,  clayey  rock,  often 
nearly  jet-black.     It  is  very  fissile,  and  .breaks  under  the 
hammer  into  thin,  slaty  fragments,  not  more  than  six  or 
eight  inches  across.    It  abounds  in  septaria,  such  as  those 
spoken  of  on  page  83,  as  resembling  turtles.    It  contains 
so  much  carbonaceous  matter  as  to  sometimes  burn  quite 
freely*    This  fact  has  led  to  much  waste  of  money  in 
exploring  it  for  coal.     The  attempts  are  always  futile, 
since  the  formation  lies  thousands  of  feet  below  the  coal 
measures. 

2.  THE  HAMILTON  GROUP*  consists  of  a  harder  and 
lighter  shaly  sandstone,  often  calcareous.     The  layers  are 
remarkable  for   the  abundance  of  ripple-marks.     They 
present  also  a  yery  perfect  jointed  structure,  some  fine 
examples  of  which  are  seen  on  Cayuga  Lake  (Fig.  25). 
It  is  extensively  used  as  a  flagging-stone,  since  it  breaks 
-into  slabs  of  great  size  and  of  uniform  thickness. 

3.  THE  GE^ESEE  SLATE  which  overlies  the  Hamilton 


BO  deeply  below  their  outlets  as  to  retain  the  accumulated  waters  of  the  rains 
and  streams,  form  that  remarkable  series  of  lakes  beginning  with  the  Otsego, 
and  comprising  the  Canaseraga,  Cazenovia,  Otisco,  Skarieateles,  Owasco,  Cay- 
uga, Seneca,  Crooked,  Canandaigua,  Honeoye,  Canadice,  Hemlock,  and  Conesus 
lakes ;  all  so  similar  in  their  general  form  and  direction,  and  in  the  shape  and 
geological  formation  of  their  inclosing  hills.  Over  the  whole  extent  of  these 
rocks,  the  country  is  "rolling"  or  broken  into  ridges  generally  running  north 
and  south,  and  rising  from  one  to  eight  hundred  feet  above  their  main  dividing 
valleys ;  and  it  is  rarely  that  we  find  among  them  a  plain  half  a  mile  in  width, 
excepting  in  a  few  of  the  "bottom-flats"  or  alluvial  lands  along  the  larger 
rivers. 

The  Hamilton  Group  in  New  York  is  overlaid  by  a  dark,  impure  rock,  termed 
the  Tully  limestone.  It  is  about  twenty  feet  in  thickness,  and  contains  a  few 
distinguishing  fossils. 

*  The  absence  of  the  Marcellus  Group  at  the  west,  drops  the  Hamilton 
directly  upon  the  Corniferous,  forming  the  appearance  of  a  single  mass.  Thus, 
four  limestone  formations— the  Niagara,  Salina,  Corniferous,  and  Hamilton— are 
there  brought  into  juxtaposition.  Before  they  were  closely  distinguished,  the 
entire  mass  was  known  as  the  "Ctiff  limestone"  because  they  often  formed  bold 
bluffs  along  the  river-banks. 


144  THE      DEVONIAN     AGE. 

beds  derives  its  name  from  the  gorge  in  the  Genesee 
river,  where  it  is  well  developed.  It  is  a  dark-blue, 
green,  and  often  black  slate,  by  which  last  name  ft  is 
known  through  the  Mississippi  valley. 


Marcellus  shale  contains  few  fossils, 
mostly  small  except  the  orthoceratite  and  goniatite.    The 


FIG.  65. 


Goniatite. 

latter  is  like  the  former,  but  is  partly  coiled,  thus  re- 
sembling the  modern  nautilus.  The  name  (gonia,  an 
angle),  refers  to  the  sinuous  form  of  the  partitions  which 
separate  the  different  chambers.  The  Hamilton  Group, 
in  its  limestone  layers,  has  fine  crinoids  and  corals,  but 
the  predominant  fossils  are  brachiopods  and  conchifers,— 
species  which  flourish  in  muddy  waters.  Among  the  for. 
mer  are  many  beautiful  ones  belonging  to  the  family  of 
spirifers.  A  peculiar  coral,  commonly  styled  the  cup 
coral  (see  1  and  7,  Fig.  67)  is  noticeable.  It  is  horn- 
shaped,  and  was  occupied  by  a  single  -polyp,  which,  when 
alive,  with  its  tentacles  expanded,  must  have  been  seven 
or  eight  inches  in  diameter.  Fish-bones  are  common  in 


DEVONIAN     CORALS. 


FIG.  67. 


-i.    Heliophyllum    Halli.      2.    Knclophyl'um   simcoense.       3.    Favosites   sothlandica. 
4    Syringopora  e!egar.s.     5.  Aulopora  con-.iitum.    C>.   Plii'lipsastra.?.  Venieuili.    7.  Zaph- 


renti-;  proliftra. 


THE     DEVONIAN     AGE. 


some  localities.     A  small  trilobite  (Phacops  bufo,  lens- 
eyed-toad)   is  conspicuous   because  of  the  perfect  pre- 


FIG.  66. 


Spirifer  mucronatus. 


servation  of  its  eye  lenses.  Terrestrial 
plants  are  an  interesting  feature,  since 
they  now  first  appear  in  any  abundance. 


CHEMUNG      PERIOD. 

Z/Ocation.  —  The  Chemung  forma- 
tion is  found  in  New  York,  attains  a 
great  thickness  in  Pennsylvania,  and  ex- 
tends west  through  Ohio. 


FIG.  68. 


Phacops  bufo. 


Kinds  of  3tocfc.  —  This  period  contains  in  New 
York  three  epochs. 

1.  THE  POKTAGE  GROUP  receives  its  name  from  the 
celebrated  falls  in  the  Genesee  Eiver.  It  consists  of 
shales  and  sandstones,  which  are  nearly  1,000  feet  thick 
at  that  locality. 


THE      C  HEM  UNO      PERIOD.  147 

2.  THE  CHEMUNG  GROUP,  named  from  the  Narrows 
in  the  Chemung  *  Biver,  is  composed  of  coarse  shales  and 
shaly  sandstones  of  an  olive  or  greenish  color. 

3.  THE  CATSKILL  GR^UP  covers  the  upper  range  of 
the  Catskill  Mountains.     It  also  consists  of  shales  and 
sandstones,  but  of  a  reddish  color,  and  oftentimes  gritty 
character.     The  harder  layers  of  the  sand-rock  sometimes 
weather  in  a  peculiar  way,  dividing  into  thin  layers  re- 
sembling a  pile  of  boards.     All  of  the  Chemung  rocks 
abound  in   ripple-marks,  mud  cracks,  and  other  proofs 
of  broad,  low  flats,  swept  by  a  muddy  sea. 


.  —  The  Portage  and  Catskill  Groups  contain 
few  fossils.  The  Chemung,  however,  in  many  localities 
abounds  in  organic  remains.  Large  slabs  are  found  com- 
pletely covered  with  impressions  of  shells.  Brachiopods 
and  cpnchifers  are  plentiful,  and  occasionally  a  trilobite 
or  an  orthoceratite  is  met.  A  prominent  brachiopod  is 
the  broad-winged  spirifer,  which  is  commonly  known  as  a 
"  petrified  butterfly."  It  resembles  the  one  shown  in 
Fig.  66.  Beautiful  fern  impressions  are  also  presented  — 
a  prophecy  of  the  abundant  vegetation  of  the  Carbonifer- 
ous Age. 


.  —  Geography.  —  The  Empire  State  is  now 
nearly  finished,  as  is  also  Wisconsin.  Interior  Mich- 
igan is  yet  an  inland  sea,  while  the  ocean  washes  in 
unrestrained  freedom  the  vast  area  of  the  Mississippi 
valley. 


*  The  name  Chemung— meaning  big  horn— was  given  to  it  by  the  In- 
dians because  of  a  mammoth  tusk  which  they  found  In  the  bed  of  the 
••iver. 


148  THE      DEVONIAN     AGE. 

SCENIC  DESCRIPTION*  -  Let  us  try  to  picture 
to  ourselves  a  scene  in  the  Devonian  landscape.  The  air 
is  yet  heavy  with  mist,  and  we  strain  our  eyes  to  catch  a 
view  of  the  land,  like  a  voyager  before  whom,  amid  the 
fogs  and  dews  of  early  twilight,  looms  an  unknown  shore. 
Gleams  of  light  here  and  there  reveal  to  us  hill-sides 
green  with  forests  of  lofty  ferns  and  club  mosses  of 
gigantic  size.  The  rivers,  fringed  with  tall,  slender 
rushes  and  reeds,  look  almost  familiar;  but  back  from 
the  banks  no  grass  carpets  the  meadows,  no  moss  clings 
to  the  rocks,  no  flowers  deck  the  landscape,  no  forests 
cover  the  mountains. 

The  sea-shore,  however,  is  stirring  with  life.  Euryp- 
teri  crawl  over  the  slimy  bottom,  and,  thrusting  out 
their  long,  muscular  arms,  draw  into  their  voracious 
maws  sea-weeds,  fish,  and  other  organic  remains  thrown 
up  by  the  tide.  Innumerable  fish,  the  armor-clad  pirates 
of  the  Devonian  seas,  impregnable  against  attack,  dart 
through  the  water  in  eager  pursuit  of  their  prey,  which 
they  crush  between  their  poniard-like  teeth.  In  the 
deeper  waters  the  coral  tribes  are  busily  at  work,  clearing 
the  water  and  building  up  the  continent,  while  on  the 
shallow,  muddy  bottoms,  shell-fish  congregate  in  myri- 
ads, furnishing  food  for  the  rapacious  monsters  of  the  deep. 

Nowhere  in  the  rocky  book  of  Nature  do  we  read  a 
page  of  quiet,  free  from  pain  or  death.  From  the  begin- 
ning the  flesh-eater  preyed  on  the  plant-eater,  and,  as  now, 
the  weak  succumbed  to  the  strong.  The  struggle  for  ex- 
istence began  with  its  gift,  and  the  reign  of  death  was  inau- 
gurated by  the  enjoyment  of  life.  Thus  only  can  Nature 
preserve  the  equipoise  between  growth  and  decay,  between 
the  means  of  subsistence  and  the  development  of  life. 


THE     C  ARBO  NIFE  ROUS    AGE. 


III.    THE    CARBONIFEROUS    AGE. 

(  i.  Sub-carboniferous  Period. 
CARBONIFEROUS  AGE.  J  2.  Carboniferous  Period. 
(3.  Permian  Period. 

This  ago   is  so  named  from  the  abundance  of  coal 
formed  in  its  time. 

FIG.  69. 


A  Carboniferous  Fern  (Sphenopteris  Egyptiaca). 

General  Characteristics  .—LI  the  beginning  of 
the  age  the  growing  continent  had  increased  by  the  sue- 


150  THE     CARBONIFEROUS     AGE* 

cessive  additions  of  the  Silurian  and  Devonian  Ages,  so 
that  the  shore-line  of  the  Atlantic  extended  through 
southern  New  York,  thence  west  through  the  southern 
part  of  Ohio,  across  the  future  Mississippi  valley.  The 
Gulf  of  Mexico  reached  north  to  central  Iowa.  Lake 
Superior  was  the  only  one  of  the  great  lakes  in  existence. 
The  pressure  of  the  waters  in  the  Atlantic  and  Pacific 
oceans  gradually  deepened  their  beds  and  produced  a 
corresponding  uplift  of  the  future  continent,  so  that  after 
a  time  the  water  drained  off  the  site  of  the  present 
southern  and  the  middle  States  south  of  the  coast  line, 
against  which  the  warm  water  of  the  Gulf  had  beaten  so 
long.  The  low  muddy  tracts,  the  former  sea-bottom, 
became  a  wide  extended  marsh,  warmed  to  a  tropical 
temperature  by  the  internal  heat.  The  atmosphere, 
dense  with  moisture,  and  containing,  in  the  form  of 
carbonic  acid,  all  the  carbon  now  locked  up  in  the  coal- 
beds,*  was  rich  in  vegetable  food.  These  favorable  con- 
ditions rendered  the  earth  a  very  greenhouse,  fit  to  teem 
with  luxuriant  vegetation.  This  same  acid,  however, 
would  have  been  fatal  to  air-breathing  animals.  Hence, 
before  they  could  be  introduced,  the  atmosphere,  must  be 
prepared  for  their  use.  Here  came  a  pause,  as  it  were,  in 
the  progress  of  the  animal  life  of  the  world.  The  plant 
must  purify  the  air  for  the  animal.  The  All^creative 
Hand,  suiting  the  means  to  the  end,  at  once  covered  the 
land  with  a  new  and  abundant  flora.  Forests  of  strange 
form  and  prodigious  size  sprang  up  as  if  by  magic  to 
meet  this  new  demand  of  Nature.  No  change  of  climate 


*  The  atmosphere  now  contains  1  part  in  2,500  of  carbonic  acid.    According 
to  M.  Brongniart,  it  had  from  7  to  8  parts  in  100  in  the  Carboniferous  Era. 


THE     CARBONIFEROUS    AGE.  151 

varied  the  productions  of  the  ground,  but  everywhere 
flourished  the  same  tropical  growth.  The  crust  of  the 
earth  was  unsteady,  and  frequent  elevations  and  depres- 
sions alternated.  At  one  time  it  was  lifted  up  to  be 
covered  with  vegetation,  and  at  another  sunk  with  the 
ruins  of  the  forests  below  the  incoming  ocean  to  receive 
a  deposit  of  sedimentary  rocks.  The  theater  of  these  re- 
peated changes  was  the  whole  of  the  present  coal  area, 
and  much  besides  from  which  the  coal  has  been  swept 
by  subsequent  denudation.  During  a  season  of  verdure  a 
vast  amount  of  vegetable  debris,  such  as  leaves,  limbs, 
fallen  trunks,  etc.,  accumulated,  only  to  be  overwhelmed 
by  the  flood  of  sand,  pebbles  and  mud  washed  in  by  the 
rushing  waters.  The  peat-deposit  gradually  changed  to 
coal,  and  the  sediment  hardened  to  shales,  sandstone, 
or  clay.  Sometimes  the  water  became  deep  and  clear 
enough  for  corals  or  mollusks  to  exist,  and  Nature,  suit- 
ing the  life  to  the  new  condition,  populated  the  shallow 
sea  with  swarming  millions,  and  there  a  limestone  was 
interpolated.  Perhaps  a  hundred  times,  in  the  course  of 
the  age  this  process  was  repeated,  and  as  many  alternate 
layers  chronicled  the  changes  in  regular  succession.  In 
a  Nova  Scotia  coal-bed  Lyell  found  in  a  portion  1,400 
feet  thick  no  less  than  sixty-eigKt  levels,  showing  as 
many  different  old  soils  of  forests,  one  above  the  other, 
where  the  trunks  of  trees  were  still  furnished  with  roots. 

These  characteristics  culminated  in  the  Carboniferous 
Period  of  the  age,  being  preceded  by  the  Sub-carbonifer- 
ous and  followed  by  the  Permian,  in  both  of  which  the 
land  of  these  formations  was  submerged  by  the  sea,  re- 
ceiving mainly  rock  deposits. 


152      THE    SUB-CARBONIFEROUS    PERIOD. 


SUB-CARBONIFEROUS    PERIOD. 


.  —  This  formation  is  so  named  because  it  is 
the  base  of  the  great  carboniferous  system  of  the  conti- 
nent. It  is  found  in  southern  New  York,  southward 
along  the  Appalachian  region,  and  westward  through 
Iowa,  Illinois,  and  Mississippi. 

J^inds  of  ffiocfc.  —  In  New  York  and  in  some  parts 
of  Pennsylvania,  Ohio,  Kentucky,  and  Tennessee,  it  is  a 
hard  conglomerate  of  quartz  pebbles  cemented  with  sand. 
It  is  very  massive  in  appearance,  and  the  ledges  often 
separate  into  huge  blocks,  with  intervening  fissures. 
Where  the  larger  portion  lias  been  swept  off  by  subse- 
quent geologic  changes,  the  remains  often  present  a 
striking  resemblance  to  the  streets  and  blocks  of  a 
ruined  city.  In  Pennsylvania  and  Virginia  it  is  over- 
laid by  a  vast  deposit  of  sandstone  and  shale  to  a  depth 
of  several  thousand  feet.  At  the  West*  it  is  a  compact 
yellowish  or  grayish  limestone,  of  great  thickness  and 
wide  extent. 

fossils.  —  The  limestone  abounds  in  crinoids.  No- 
where else  are  these  stone-lilies  —  the  blossoms  of  the  Sub- 


*  The  following  arc  the  subdivisions  in  Illinois,  given  by  Worthen : 

1.  The  Chester  Group,  500  to  800  feet  thick. 

2.  The  St.  Louis  Group,  50  to  200  feet  thick. 

3.  The  Keokuk  Group,  100  to  150  feet  thick. 

4.  Burlington  Limestone,  25  to  200  feet  thick. 

5.  Kinderhook  Group,  100  to  150  feet  thick. 

The  Marshall  Group,  so  named  from  Marshall,  Michigan,  is  doubtless,  ill  part 
at  least,  of  this  period.  It  is  worked  at  Cleveland  and  Waverly,  Ohio,  furnishes 
the  grindstones  of  Berea  and  Huron,  and  underlies  the  limestone  bluff  at  Burling- 
ton, Iowa.  Dana  thinks  the  Kinderhook  and  Marshall  groups  are  on  about  the 
same  creolojnc  horizon. 


THE    SUB-CARBONIFEROUS    PERIOD.      153 

carboniferous  sea — found  in  such  profusion  and  beauty. 
There  are  also  many  brachiopods  and  fish  remains.  In 
England  this  rock  is  termed  the  Mountain  Limestone. 
When  the  stone  is  worn  away  by  the  elements,  the  round, 
hard  joints  of  the  crinoids  are  found  lying  loose  in  the 
soil,  and  are  gathered  and  strung.as  beads  by  the  children.* 

7) Ciller iiS. — /.  Cares.  —  Many  of  the  most  famous 
caves  are  in  this  rock;  for  example,  the  Mammoth 
Cave,  the  Wyandotte  Cave,  etc.  In  many  places  in 
Indiana  and  Kentucky,  "sink-holes"  are  abundant, 
sometimes  so  numerous  as  to  interfere  with  plowing. 
These  are  openings  in  the  earth  where  the  soil  has  been 
washed  down  probably  into  subterranean  caves  never 
yet  seen  by  man.  The  Mammoth  Cave  is  the  largest  in 
the  World.  It  has  been  explored  to  a  distance  of  over 
thirty  miles.  Views  of  the  grandest  description  are  con- 
stantly presented.  Eoyal  thrones,  sparry  grottoes,  dia- 
mond arches,  flowers  of  every  zone  sparkling  with  crys- 
talline beauty,  reflect  the  light  of  the  traveler's  torch. 
Stalactite  halls  decorated  with  fantastic  pillars,  and  mar- 


*  Thus  Sir  Walter  Scott,  in  allusion  to  the  popular  fable  concerning  this  for- 
mation, eays : 

41  But  fain  St.  Hilda's  nuns  would  learn 

If  on  a  rock  by  Lindisferne 
-     St.  Cuthbert  sits,  and  toils  to  fr.ime 
The  sea-born  beads  that  bear  his  narao : 
Such  tales  had  Whitby's  fishers  told. 
And  said  they  might  his  shape  behold, 

And  hear  his  anvil  sound, — 
A  deadened  clang,  a  huge,  dim  form, 
Seen  but  and  heard  when  gathering  storm 
And  night  were  closing  round.1" 

Hugh  Miller  humorously  remarks  that  if  St.  Cuthbert  made  all  these  beads,  he 
must  have  been  the  busiest  saint  in  the  calendar. 


154  THE     CARBONIFEROUS    AGE. 

ble  statues  draped  with  crystal  mantles,  charm  with  their 
magical  splendor.  At  one  point  the  River  Styx  rolls  its 
sad  waters  beneath  dark  vaults,  the  windings  of  which 
are  indented  by  a  thousand  rocks.  In  its  dismal  depths 
gropes  a  kind  of  fish — the  Cyprinodon — which  is  blind, 
as  it  should  be,  since  of  what  service  are  eyes  where 
absolute  darkness  reigns  ? 

2.  ^Reptiles.  —  In  Sub-carboniferous  rocks  at  Potts- 
ville,  Pa.,  the  footprints  of  a  reptile,  having  a  stride  of 
thirteen  inches,  have  been  found.  Later  in  the  age,  there 
appear  many  advance  scouts,  as  it  were,  of  the  reptilian 
hosts  of  the  succeeding  age. 

CARBONIFEROUS       PERIOD, 

^Location. — The  great  coal-beds  of  the  country  lie  in 
six  detached  areas  as  seen  in  the  Frontispiece.  They  are 
styled  respectively  the  Rhode  Island,  Appalachian,  Michi- 
gan, Illinois,  Missouri,  and  Texas  coal-fields.  The  Rhode 
Island  is  the  smallest,  and  comprises  an  area  of  only 
1,000  square  miles  ;  the  Missouri  is  the  largest,  and 
covers  100,000  square  miles. 

J&nds  of  ffiock.  —  The  Carboniferous  Period  was 
inaugurated  by  the  formation  of  a  great ' conglomerate 
sandstone  known  as  the  Millstone  Grit.  As  it  often  con- 
tains thin  seams  of  coal,  it  is  frequently  termed  the  False 
Coal  Measures.  During  this  era  of  convulsion,  the  fishes 
and  ferns  of  the  Devonian  Age  were  buried  deep  beneath 
vast  accumulations  of  lifeless  sand  and  gravel.  This  was 
interrupted,  however,  by  frequent  times  of  quiet,  when, 


THE     CARBONIFEROUS     PERIOD.  155 

for  a  brief  interval,  the  land  was  partially  clothed  with 
vegetation.  The  coal-measures  proper  present  stratified 
rocks  of  every  kind— sandstone,  shales,  limestone,  etc. 
They  can  be  distinguished  from  Silurian  or  Devonian 
strata  only  by  the  fossils.  There  is  generally  about  one 
foot  of  coal  to  fifty  feet  of  rock.  The  thickness  of  the 
coal-bed  is  at  some  places  only  that  of  paper,  and  at 
others  from  thirty  to  forty  feet.  The  "mammoth  vein " 
exposed  to  view  at  Wilkesbarre,  and  worked  at  Carbon- 
dale,  Mauch  Chunk,  Shamokin,  etc.,  is  29J  feet  thick.* 
The  Pittsburg  seam  is  8  feet  thick,  and  may  be  traced  for 
a  long  distance  as  a  conspicuous  black  band  along  the 
high  banks  of  the  Monongahela.  The  miners  estimate 
that  a  coal-bed  gives  1,000,000  tons  to  the  square  mile 
for  every  foot  of  thickness.  Iron  ore  is  also  abundant. 
Iron  pyrites  (sulphuret  of  iron)  is  distributed  either  in 
nodules,  often  of  many  pounds  weight,  or  in  thin  seams, 
so  as  to  greatly  injure  the  coal.  The  best  quality  of  coal 
contains  a  trace  of  this  impurity,  which  gives  the  disagree- 
able odor  of  coal-gas. 

Fossils \ — I.  PLANTS  are  the  characteristic  fossils  of 
this  period.   Everywhere  the  shales  bear  impress  of  the  deli- 


*  "  The  amount  of  vegetable  matter  in  a  single  coal-seam  six  inches  thick  is 
greater  than  the  most  luxuriant  vegetation  of  the  present  day  would  furnish  in 
1,200  years.  Boussingault  calculates  that  luxuriant  vegetation  at  the  present 
day  takes  from  the  atmosphere  about  half  a  ton  of  carbon  per  acre  annually,  or 
fifty  tons  per  acre  in  a  century.  Fifty  tons  of  stone-coal,  spread  evenly  over  an 
acre  of  surface,  would  make  a  layer  of  less  than  one-third  of  an  inch.  But  sup- 
pose it  to  be  half  an  inch,  then  the  time  required  for  the  accumulation  of  a  seam 
of  coal  three  feet  thick — the  thinnest  which  can  be  worked  to  advantage — would 
be  7,200  years.  If  the  aggregate  thickness  of  all  the  seams  of  coal  in  any  basin 
amounts  to  sixty  feet,  the  time  required  for  its  accumulation  would  be  144,000 
years.  In  the  coal  measures  of  Nova  Scotia  are  seventy-six  Reams  of  coal,  of 
which  one  is  twenty -two  feet  thick,  and  another  thirty-seven."—  WincheWs  Geo- 
logical Sketches. 


156  THE     C  A  R  B  0  XIFE  R  0  US     A  G  E. 

cate  tracery  of  ferns,  leaves,  stems,  depicted  with  the 
sharpest  outlines.*  Trunks  of  trees,  erect  or  prostrate, 
appear  with  their  roots  yet  imbedded  in  the  layer  of  clay, 
the  very  soil  in  which  they  grew,  underneath  the  coal. 
These  fossils  reveal  to  us  most  perfectly  the  vegetation  of 
the  Period.  It  is  the  fulfillment  of  that  which  scantily 
appeared  in  the  Devonian  Age.  It  was  almost  entirely  a 
flowerless  growth.  The  leading  forms  were  tree-ferns, 
rushes,  and  club-mosses,  which  grew  to  a  size  unknown 
in  our  climate.  If  we  should  collect  the  cryptogams 
(flowerless  plants)  of  North  America  to  form  a  forest, 
it  would  hardly  overtop  a  man's  head,  and  the  ferns 
would  have  an  undergrowth  of  toad-stools,  mosses,  and 
lichens  (Dana). 

1.  The  Ferns. — Ferns  which  to-day  creep  at  our  feet, 
then  towered  into  stately  trees,  with  trunks  a  foot  and  a 
half  in  diameter.     They  are  abundant  fossils,  and  doubt- 
less contributed  most  to  the  formation  of  coal. 

2.  The  Calainites  wrere  jointed,  rush-like  plants.    Un- 
like the  " horse-tail"  or  "scouring  rushes"  of  the  pres- 
ent, which  are  rarely  two  feet  long,  their  Carboniferous 
prototypes   shot   up   like   a   gigantic   asparagus,   with   a 
woody  fiber,  to  a  height  of  a  score  or  more  of  feet.     The 
impressions  of  their  huge  prostrate  stems  are  frequent. 


*  "  The  most  elaborate  imitations  of  living  foliage  upon  the  painted  ceilings 
of  Italian  palaces,  bear  no  comparison  with  the  beauteous  profusion  with  which 
*,he  galleries  of  these  instructive  coal  mines  are  overhung.  The  roof  is  covered 
as  with  a  canopy  of  gorgeous  tapestry,  enriched  with  festoons  of  most  graceful 
foliage,  flung  in  wild  irregular  profusion  over  every  portion  of  its  surface.  The 
effect  is  heightened  by  the  contrast  of  the  coal-black  color  of  these  vegetables 
with  the  light  ground- work  of  the  rock  to  which  they  are  attached.  The  spec- 
tator feels  himself  transported,  as  if  by  enchantment,  into  the  forests  of  another 
world ;  he  beholds  trees  of  forms  and  characters  now  xiuknown  upon  the  sur- 
face of  the  earth,  presented  to  his  senses  almost  in  the  beauty  and  vigor  of  their 
primeval  life.1'— Dr.  Buckland. 


T II E     C  A  R  B  O  XIFE R  0  US     PERIOD.  151 

3.  The  Sigillaria    (seal -marked)    is    curiously   orna' 
merited:  with  vertical  ribs,  along  each  of  which  is  a  row 
of  seal-like  impressions.     These  are  the  scars  left  where 
the  leaves  fell  off.     They  wind  in  a  spiral  around  the 
trunk.    The  roots  (stigmaricB)  are  also  dotted  with  scars. 
They   arc  generally  found   separate,   though   sometimes 
combined   with   the  parent  tree.     The   sigillarian  tree- 
trunks  frequently  occur  standing  in  coal   mines.      The 
miners  sometimes  cut  them  off  below,  when  their  taper- 
ing form  permits  the  whole  mass  to  descend  upon  the 
workmen  beneath.    These  "coal-pipes,"  as  they  are  styled, 
are  therefore  much  dreaded. 

4.  The   Lepidodcndra   (scaly-steins) — the   club-rnosscs 
of  that  time — were  lofty  trees,  sixty  feet  high,  with  pitted 
trunks  and  branches.     The  scars  arc  arranged  diagonally 
or  in  a  quincunx  order. 

5.  Conifers,  or  cone-bearing  trees,  were  not  infrequent, 
with  their  boughs  laden  with  fruit.     Such  was  the  vege- 
tation which   flourished   in  the  Carboniferous  Age,  and 
which  we  now  use  to  warm  and  light  our  houses  and  to 
drive  our  engines. 

II.  ANIMALS. — In  a  coal  mine  near  the  Bay  of  Fundy, 
in  the  stumps  of  two  sigillariae,  there  have  been  found  the 
remains  of  several  small  reptiles  bearing  frog-like  and 
lizard-like  forms,  a  centipede,  and  the  shell  of  a  land 
snail.  These  little  creatures  had  probably  crept  into 
these  hollow  trees  for  shelter,  and  were  overtaken  by 
the  convulsions  which  overwhelmed  them.  Several  larger 
fossil  reptiles  have  since  been  identified.  Two  or  three 
species  of  insects,  with  broad  gauze  wings,  like  the 
dragon-fly,  have  also  been  discovered.  Remains  of  fishes, 


FIG.  70. 


CARBONIFEROUS   FOSSILS. 


I.  Calamites  cistii.  2.  Archimedes  Worthu. 

3.  Asterophyllites  equisetiformis.  4.  Actinocrinus  chrvstii. 

5.   Sijjillaria  attenuata.  6.   Pentremites  Godoni. 

7.   Pentremites  pyriformis.  8.   Pentremites  Koninckana. 

(4,  6,  7  and  8  are  varieties  of  Crinoid?O 


. 


• 


; 


G)I  ,-3  —  rz 
vyit^k^^t: 


i 


I 


THE     CARBONIFEROUS     PERIOD.          161 

brachiopods,  crinoids    and  corals  are    abundant.      (See 
Pig.  70.) 

SCENIC  DESCRIPTIOIT.-In  Fig.  71  is  an  at- 
tempt to  reproduce  the  characteristic  features  of  a  car- 
boniferous landscape.  On  the  right  are  two  naked  trunks 
of  a  lepidodendron  and  sigillaria  (whose  foliage  is  entirely 
unknown);  between  them  is  a  tall  tree-fern  with  its  um- 
brella-like top.  At  the  foot  of  these  great  trees  are 
smaller  ferns,  and,  in  front,  a  stigmaria,  whose  curiously 
dotted  and  branching  roots  reach  out  into  the  water.  On 
the  extreme  left  is  an  asterophyllite,  like  the  calamitc, 
with  its  gigantic  bamboo-like  trunk.  Next  is  a  conifer, 
with  a  few  pine-like  branches.  In  front  is  a  sigillaria, 
and  at  its  foot,  prostrate,  a  sigillaria  and  a  lepidoden- 
dron mingled  with  ferns  and  vegetable  debris.  In  the 
centre  is  a  clump  of  smaller  lepidodendra.  The  back- 
ground is  filled  with  tall  calamites.  In  the  foreground 
are  the  asparagus-like  buds  of  young  calamites  just  rising 
out  of  the  water.  At  the  right  several  tiny  stems  of 
asterophyllites  show  their  pretty,  finely-cut  branches.  In 
the  water  float  two  fishes,  and  the  archegosaurus  shows 
its  long-pointed  head. 

What  a  strange  scene  is  presented  as  we  stem  the 
muddy  current  of  the  sluggish  rivers,  or  thread  the 
mazes  of  those  tropical  jungles.  It  is  as  if  the  plants 
of  a  wet  meadow  had  shot  up  into  forest  trees.  The 
trunks,  not  gnarled  and  rough  as  in  modern  times, 
spring  up  like  the  sculptured  shafts  of  a  medieval  temple, 
graceful  in  proportion  arid  rich  in  ornament.  Each  col- 
umn is  embossed  with  its  varied  fluting  spirals  and  ovals 
of  curiously  intricate  patterns.  T]ie  tall  ferns  at  every 


162  THE      CARBONIFEROUS      AGE. 

breath  of  wind  wave  their  feathery  crowns  like  beautiful 
plumes.  The  scent  of  the  morning  air  is  hot  and  damp 
as  that  of  a  greenhouse.  The  sky,  ever  somber  and 
veiled,  shuts  down  heavy  with  oppressive  clouds.  A  wan 
and  dubious  light  scarcely  makes  visible  the  tangled 
stems  of  lepidodendra  and  sigillarise,  and  sheds  a  vague 
and  shadowy  hue  of  horror  over  the  scene.  The  flowers, 
few  and  inconspicuous,  fail  to  enliven  the  somber  tints 
with  a  gayer  color.  No  song  of  bird,  and  rarely  the 
hum  of  insect  is  heard;  and,  save  when  the  alligator- 
like  bellowings  of  the  archegosaurus  wake  the  echoes  of 
this  dismal  .forest,  the  awful  silence  is  supreme. 

THE    PERMIAN     PERIOD. 

ZrOcation. — This  formation  is  named  from  the  an- 
cient kingdom  of  Permia,  in  Russia,  where  it  was  first 
recognized.  It  is  wanting  in  the  older  States,  but  is 
well  developed  in  Kansas,  and  has  been  recognized  in 
Nebraska  and  Texas. 

J£inds  of  ffiocfc. — Limestones  predominate,  though 
sandstone,  shales,  etc.,  are  found.  At  Manhattan,  Kan., 
a  limestone  is  quarried  from  this  series  for  architectural 
purposes,  which  is  so  soft  that  it  may  be  sawed  with  a 
hand-saw  and  planed  with  a  jack-plane,  and  yet  is  very 
durable.  It  is  the  cheapest  material  of  which  the  pioneer 
can  construct  his  house — cheaper  even  than  it  would  be 
to  resort  to  the  forest,  if  such  existed,  for  logs  (Foster). 
Hayden  notices  the  occurrence  of  a  similar  limestone, 
and.  belonging  to  the  same  age,  in  Nebraska.  The  best 
building  material  in  England  is  the  Permian  lime- 


THE     PERMIAN    PERIOD.  163 

stone  of  which  the  new  houses  of  Parliament  are  con- 
structed. 

Fossils.  —  The  Permian  system  is  more  a  new  rock- 
formation  than  a  new  life-period.  Many  of  its  forms  are 
identical  with  those  of  the  Carboniferous  Period.  The 
air  has  been  cleared  by  the  action  of  the  abundant  vege- 
tation, and  the  empire  of  animal  life  trembles  between 
the  fishes  and  reptiles.  The  former  are  decreasing,  while 
the  latter  are  increasing  in  size  and  number.  The  first 
definite  reptiles  are  seen,  while  the  old  armor-clad  fishes 
disappear.  The  coal  flora  has  not  entirely  died,  though 
the  coal-making  epoch  is  passed  ;  the  low  swampy  lands 
seem  to  have  been  raised  so  as  to  be  unfavorable  to  its 
growth,  and  no  new  vegetation  fills  the  place.  It  is  near- 
ing  the  close  of  the  great  Paleozoic  Time.  Older  forms 
are  dying,  and  the  Creator  develops  no  fresh  world- 
thoughts  to  mark  the  dawn  of  a  new  era.  The  coal  is 
stored  in  the  earth,  and  the  continent  now  moves  for- 
ward in  its  preparation  for  the  advent  of  man,  for  whom 
it  has  been  so  wonderfully  contrived. 


.—  /•  dppatactiian  Devolution.—  -The 
close  of  the  Palaeozoic  Age  was  marked  by  terrific  con- 
vulsions. Neither  animal  nor  plant  survived  the  catas- 
trophe. The  tremendous  pressure  of  the  two  oceans 
during  the  Carboniferous  Age,  had  kept  the  newly- 
formed  continent  continually  vibrating  to  and  fro;  but 
at  last  the  tension  was  too  great,  and  the  crust  was  up- 
heaved in  gigantic  folds  thousands  of  feet  high,  extending 
from  Vermont  to  Alabama.  The  Appalachians,  being 
nearest  the  Atlantic  force,  were  thrown  up  far  higher 


164  THE     CA  K  B  0  NIFER  O  US     AGE. 

than  they  are  at  present,  often  toppling  over  from  their 
dizzy  heights,  while  more  gentle  elevations  were  made 
toward  the  central  portion  of  the  continent.  Since  then 
many  of  these  folds  have  been  denuded.  A  striking 
illustration,  occurring  near  Chambersburg,  Pennsylvania, 
has  already  been  alluded  to  on  page  82.  At  that  point, 
along  a  fracture  of  twenty  miles  in  extent,  rocks  of  the 
Upper  Silurian  lie  opposite  those  of  the'  Lower.  A  man 
can  stand  astride  the  crevice  with  one  foot  on  Trenton, 
limestone  and  the  other  011  Hamilton  slates,  and,  in  addi- 
tion, put  his  hand  on  some  great  fragments  of  Oneida 
conglomerate,  caught  as  they  were  falling  down  the 
chasm,  and  held  in  its  earthquake  jaws.  All  the  strata 
between  these  two  extremes,  at  the  time  of  the  Appala- 
chian Kevolution,  must  have  formed  an  immense  wall 
20,000  feet  high  and  twenty  miles  in  length. 

Metamorphic  Action. — This  fearful  earth-storm 
sweeping  over  the  continent  not  only  twisted  and  dislo- 
cated the  horizontal  coal-beds,  but  lifted  them  above 
their  former  level.  An  evolution  of  the  internal  heat 
accompanied  the  convulsion,  and  thus  the  bituminous 
coal  was  metamorphosed  into  anthracite.  This  effect, 
like  that  seen  in  the  rock  strata,  was  most  felt  near  the 
Atlantic  coast;  hence  we  find  anthracite  coal  in  the  Ap- 
palachian Mountains,  next  semi-bituminous,  and  in  the 
western  area  bituminous  coal  alone.  The  same  meta- 
morphic  force,  where  greatest,  as  in  the  eastern  States, > 
produced  granite,  gneiss,  and  other  crystalline  rocks. 
Nine-tenths  of  the  rocks  on  the  surface  of  the  globe"  were 
made  prior  to  this  period.  Many  of  these  beds  during 
this  revolution  were  crystallized,  and  also  stored  with 


THE     PERMIAN     PERIOD.  U'>~) 

mines  of  gold,  tin,  copper,  lead,  etc.,  thus  fitting  them 
for  the  purposes  of  art  and  commerce. 

2.  'Progress  of  Z,ife. — We  have  beheld  seas— vast 
watery  deserts — become  densely  populated.  We  have 
traced  the  Creative  thought  slowly  advancing  among 
the  ruins  of  ages.  A  vast  progress  has  been  made  in 
the  life  of  the  world.  The  four  types  of  structure  have 
all  been  introduced,  and  all,  except  the  vertebrate,  devel- 
oped to  their  highest  orders.  The  lower  forms  have,  one 
by  one,  given  place  to  the  higher.  We  now  pass  over  a 
chasm  to  where  the  distinctions  stand  out  in  bold  relief. 
We  take  leave  of  the  trilobites,  graptolites,  orthoceratites, 
eurypteri  and  corals  of  the  Silurian  seas,  of  the  mail- 
encased  fishes  of  the  Old  Eed  Sandstone,  of  the  sigil- 
larias,  stigmariae,  and  lepidodendra  of  the  Carboniferous 
jungles,  and  go  forward  to  meet  higher  forms  of  life 
more  nearly  resembling  those  of  the  present  age.  The 
Palaeozoic  types  fade  away  in  the  world's  progress  to  its 
brighter  future.  "  As  the  stars  sink,  one  by  one,  in  the 
west,  and  new  stars  rise  in  the  east,  to  be  succeeded  by 
the  dawn  and  then  the  day,  so  through  the  night  of  the 
past  sank  the  old  life-forms,  to  be  succeeded  by  the  new, 
approaching  nearer  to  the  dawn  of  the  day  in  whose 
morning  we  live."  (Denton.) 


166  THE     AGE      OF     REPTILES. 


IHE    if-Esozoie    fiME. 


The  Mesozoic  or  Middle-life  of  Geologic  History  com- 
prises but  one  age,  that  of  reptiles. 

[    i.  Triassic  Period. 
THE  AGE  OF  REPTILES.    •'    2.  Jurassic  Period. 

(    3.  Cretaceous  Period. 

General  Characteristics. — A  new  cycle  now  be- 
gins. The  four  grand  old  types  of  life  remain,  but  they 
are  presented  under  new  and  more  familiar  features. 
The  four  orders  of  vertebrates  are  at  last  complete.  The 
air  is  purified  for  land  animals.  A  flora  arises  capable 
of  supporting  a  more  abundant  fauna.  Birds,  mam- 
mals, common  or  bony  fishes,  palms  and  flowering  plants 
appear.  The  plants  of  the  Palaeozoic  were  mainly  endo- 
gens  (in-growers),  i.  e.,  plants  which  grow  by  increasing 
.within,  like  the  corn,  cane,  etc.  To  these  are  now 
added  cxogens  (out-growers),  i.  e.,  plants  which  grow  by 
external  layers  of  annual  increase,  like  the  beech,  oak, 
etc.  The  endogens  have  leaves  with  parallel  veins,  and 
the  parts  of  the  flowers  arranged  by  threes;  the  exogens 
have  leaves  with  net-veins,  and  the  parts  of  the  flowers 
commonly  arranged  by  Jives.  The  former  expand,  and 
make  their  development  mainly  in  the  sculptured  stem ; 
the  latter,  in  the  beauty  of  fruit  and  flower.  The  Palaeo- 
zoic corals  had  rays  or  arms  arranged  in  fours;  the  later 
corals,  in  ^sixes.  The  Palaeozoic  chambered  shells  had 
plain  and  simple  divisions ;  the  later  shells  have  intricately- 


TRIASSIC    AND    JURASSIC    PERIODS.^    107 

folded  ones.  The  Palaeozoic  fishes  had  tails  unequally 
lobed ;  since  then,  the  equally-lobed  or  undivided  tail  has 
been  the  usual  form.  Aside  from  these  general  features, 
the  distinguishing  characteristic  of  the  Mesozoic  Time  is 
the  extraordinary  development  of  reptiles.  These  ani- 
mals astonish  us  by  their  vast  number,  gigantic  size,  and 
unwonted  appearance.  Through  those  antique  forests 
enormous  lizards,  forty  to  fifty  feet  in  length,  dragged 
their  ponderous  bodies, — the  modern  representatives  of 
which  are  inoffensive  little  creatures  a  few  inches  long, 
that  seek  only  to  hide  from  our  view  in  the  grass. 

Geograpfiy '. — The  continent  has  grown  by  the 
addition  of  the  Carboniferous  area.  The  Appalachian 
region  has  been  uplifted  above  the  sea.  The  scene  of 
rock-making  is  pushed  to  the  borders  of  the  Atlantic  and 
the  Gulf,  and  to  the  slopes  of  the  Eocky  Mountains.  The 
accompanying  map  is  an  attempt  to  show  some  of  the 
outlines  of  the  Mesozoic  continent.  New  England  was  a 
peninsula.  The  beautiful  valley  of  the  Connecticut  was 
an  arm  of  the  ocean,  with  broad,  flat,  muddy  shores. 
The  Gulf  States  were  out  at  sea.  The  Gulf  of  Mexico 
swept  along  the  eastern  flank  of  the  Eocky  Mountains  to 
the  Arctic  Ocean,  while  the  Pacific  Ocean  laved  the  west- 
ern flank  of  the  Sierra  Nevada.  New  Jersey,  Maryland, 
Delaware,  North  and  South  Carolina,  were  as  yet  only 
half  made.  (See  Fig.  72.) 

TRIASSIC    AND     JURASSIC     PERIODS, 

These  groups  are  not  fully  separated  in  America.  The 
Triassic  (triple)  takes  it  name  from  the  fact  that,  in  Ger- 


168 


THE      A  G  E      O  F     R  E  P  TIL  E  S. 


many  it  is  composed  of  three  distinct  groups.*  It  is 
sometimes  termed  the  New  Red  Sandstone,  to  distinguish 
it  from  the  Old  Eed  Sandstone  of  the  Devonian.  The 
Jurassic  is  so  called  because  it  is  extensively  developed  in 
the  Jura  Mountains,  Switzerland.  The  foreign  divisions 
are  the  Lias,  Oolite,  and  Wealden. 

FIG.  72. 


The  Mesozoic  Continent. 


j£ocation.  —  ln  the  United  States  the  rocks  of  this 
period  are  found    along   the   Connecticut  Valley   from 


*  The  Hunter  Sandstein  or  colored  sandstone,  the  Muschelkalk  or  mussel 
chalk,  and  the  Keuper,  a  miner's  term,  meaning  a  group  of  red  and  green  marls 
and  shells. 


TRIASSIC     AND     JURASSIC     PERIODS.    169 

Long  Island  Sound  to  the  northern  boundary  of  Massa- 
chusetts ;  thence  they  may  be  traced  from  the  Palisades 
on  the  Hudson,  in  long,  narrow,  scattered  strips  through 
New  Jersey,  Pennsylvania,  Virginia,  and  North  Carolina. 
(See  Frontispiece.)  They  probably  occupy  the  synclinal 
valleys  running  north  and  south,  left  between  the  great 
folds  of  the  Appalachian  Eevolution.  During  that  time 
they  were  under  the  water,  and  formed  deep  inland  bays, 
receiving  the  washings  from  adjacent  hills  to  work  into 
rock  formations.  The  beds  are  from  3,000  to  6,000 
feet  thick;  hence  these  valleys  must  have  constantly  set- 
tled and  as  steadily  filled  with  the  accumulating  sedi- 
ment. The  great  Pacific  Triassic  belt  extends  from 
Mexico  to  British  Columbia,  through  a  width  of  per- 
haps four  degrees  of  longitude  (Whitney).  The  rocks 
are  also  found  extensively  in  Colorado  and  Nevada. 

ICinds  of  ffiocfc.  —  The  rocks  of  the  Connecticut 
valley  are  principally  sandstones,  which  are  extensively 
quarried  for  the  "  brown-stone  fronts  "  of  New  York  city. 
The  popular  "  free-stone "  of  Portland,  Conn.,  and  New- 
ark, N.  J.,  is  a  Triassic  rock.  Near  Richmond,  Va.,  and 
Deep  River,  N.  C.,  are  valuable  coal  beds  in  the  rocks  of 
this  era.  At  the  west  this  formation  consists  of  beds  of 
brick-red  marl  and  sandstone.  The  celebrated  Solen- 
hofen  limestone,  so  much  used  in  lithography,  is  of  the 
Jurassic  Period. 

Fossils. — The  organic  remains  are  of  the  most  varied 
and  wonderful  description.  They  reveal  very  clearly  the 
plant  and  animal  life  of  these  periods. 

I.  PLANTS. — The  vegetation  included  numerous  varie- 
8 


170 


THE   AGE      OF    REPTILES. 


ties  of  ferns,  conifers,  and  calamites,  which  formed 
graceful  forests,  as  in  the  Carboniferous  Period;  but 
^there  were  no  jungles  of  lepidodendra  or  sigillariae.  In- 
stead of  these,  the  Cycad  appeared.  This  had  a  short 
trunk,  and  at  the  top  a  tuft  of  branching  leaves  (Fig.  82, 
left  of  the  center).  In  shape,  the  leaves  resembled  those 
of  the  palm,  but  did  not  split  lengthwise,  while  they 
unrolled  from  a  coil,  like  those  of  the  fern.  The  struc- 
ture of  the  wood  and  fruit  was  like  that  of  the  conifers. 
The  cycad,  combining  thus  characteristics  of  three  orders 
of  plants — conifers,  ferns,  and  palms — is  another  illus- 
tration of  what  we  have  termed  a  comprehensive  type. 

II.  AKIMALS. — Birds  and  mammals  make  their  first 
appearance,  completing  the  last  and  highest  order  of 
animals.  Spiders,  beetles  and  other  insects  have  been 
discovered,  and  even  their  tracks  in  the  soft  mud  have 
been  preserved.  Fish  remains  are  plentiful,  as  at  Sun- 


FIG.  73. 


FIG.  74- 


Ostrea  marshii.     Middle  O51ite. 


Trails   of  Insects  and  Prints  of 
Rain-drops. 


derland,  Mass.    Fig.  73  represents  an  Oolitic  oyster,  the 
progenitor  of  our  modern  bivalve.      Marine   life   seems 


TRIASS1C    AND    JURASSIC    PERIODS.    171 

wanting  in  this  country,  but  the  European  rocks  contain 
a  prolific  record  of  the  Mesozoic  seas.  Crinoids  were 
abundant ;  one  of  these,  the  Lily  Encrinite,  is  especially 
beautiful  (Fig.  75).  The  cephalopods  reached  their  cul- 
mination in  the  ammonite  and  belemnite. 
FIG.  75. 


Encrinite  (krine,  a  lily)  raoniliformis  (from  the  necklace  shape  of  the  stalk). 


The  Ammonite  is  the  fully  coiled  and  perfected  or- 
thoceratite  of  the  Silurian  seas.  It  derives  its  name  from 
its  resemblance  to  the  horn  which  decorated  the  front 
of  the  temple  of  Jupiter  Ammon  and  the  bas-reliefs  and 
statues  of  that  pagan  deity.  It  is  found  of  all  sizes,  from 
that  of  a  pin's-head  to  a  cart-wheel.  The  shell  is  thin, 
but  strengthened  by  many  sinuous  partitions  (septa), 
which  add  to  its  beauty  and  strength.*  This  curious 
internal  archwork,  by  its  joinings  with  the  external  shell, 

*  The  economy  of  the  Ammonite  designed  it  to  live  mainly  at  the  bottom  of 
deep  waters,  but  to  be  able  to  rise  at  pleasure  to  the  surface.  For  this  purpose 
the  outer  chamber  (0  o)  (Fig.  76)  of  the  wreathed  shell  was  fitted  for  the  reception 
of  the  animal,  while  the  interior  chambers  (i  i)  were  hollow,  so  as  to  make  the 
whole  structure  nearly  of  the  same  weight  as  the  element  in  which  it  moved. 
Through  all  of  these  chambers  an  elastic  tube  passed  by  means  of  a  pipe  or 
siphuncle  («  s),  the  tube  being  in  connection  with  the  cavity  of  the  heart,  which, 
under  ordinary  circumstances,  was  filled  with  a  dense  fluid.  When  alarmed,  or 
wishing  to  descend,  the  animal  withdrew  itself  within  the  outer  chamber,  and 
the  pressure  upon  the  cavity  of  the  heart  forced  the  fluid  into  the  siphuncle,  so 
as  to  increase  the  gravity  of  the  shell,  by  which  means  it  readily  sunk  to  the 
bottom.  On  the  other  hand,  when  wishing  to  ascend,  it  had  only  to  project  its 
arms,  and  the  fluid,  being  freed  from  the  pressure,  returned  from  the  siphuncle 
to  the  cavity  of  the  heart,  thus  restoring  the  whole  structure  to  its  ordinary 
floating  gravity.  As  the  pressure  of  water  at  the  sea-bottom  would  break  any 
ordinary  shell,  we  perceive  that  the  septa  were  essential  to  the  preservation  of 
the  little  animal,  enabling  it  to  resist  a  weight  which  would  otherwise  crush  it. 


'17* 


THE     AGE     OF    REPTILES. 


adorns  it  with  graceful  figures  resembling  the  most  deli- 
cate foliage  or  embroidery.  The  chambers  are  often 
found  lined  with  quartz  crystals,  making  tiny  geodes  of 


FIGS.  76-7. 


i.  Ammonites  obtusus ;  2.  Section  of  Ammonites  obtusus,  showing  the  interior  cham- 
bers and  siphuncle ;  3.  Ammonites  nodosus. 

exquisite  beauty,  while  the  edges  of  the  partitions,  being 
converted  into  iron  pyrites,  form  a  kind  of  golden  tra- 
cery, glittering  in  the  midst  of  the  pellucid  spar.  The 
only  surviving  member  of  this  family  is  the  modern 
nautilus  (naus,  a  ship),  the  "fairy  sailor"  of  the  Indian 
seas. 

The  Belemnite  (lelemnon,  a  dart)  is  so  called  from  the 
peculiar  shape  of  the  fossil  (Fig.  78).     They  have   also 

FIG..  78.  - 


Belemnitella  mucronata,  Cretaceous  Period,  N.  J. 

been  vulgarly  called  "  thunder-heads,"  "  lady-fingers,"  etc. 
The  relics  do  not  give  any  idea  of  the  animal  to  which 
the  name  was  applied.  They  were  merely  the  terminal 
bones  of  the  body  and  were  surrounded  with  flesh.  The 


TRIASSIC    AND    JURASSIC    PERIODS.      173 


FIG.  79. 


animal  resembled  the  modern  cuttle-fish.*  It  secreted 
a  kind  of  ink  which  it  used  as  a  means  of  defence. 
In  an  emergency,  it  blackened  the 
water  in  its  vicinity,  and  escaped 
from  sight.  These  ink-bags  have 
been  found  so  perfectly  preserved 
that  their  contents  have  been  used 
in  sketching  their  fossil  remains. 

The  enormous  reptiles  are,  how- 
ever, the  distinguishing  fossils  of  the 
age.  We  shall  notice  only  the  more 
prominent  ones. 

1.  The  IcJithyosaur  (fish-lizard)  is 
a  striking  illustration  of  a  compre- 
hensive type,  having  the  general  con- 
tour of  a  dolphin,  the  snout  of  a 
porpoise,  the  head  of  a  lizard,  the 
jaws  and  teeth  of  a  crocodile,  the 
vertebras  of  a  fish,  the  sternal  arch 
of  the  water-mole, f  the  paddles  of 
a  whale,  and  the  trunk  and  tail  of 
a  quadruped.  Its  habits  were  doubt- 
less aquatic,  while,  like  the  whale, 

,.,  ,  ,  Belemnite  restored ;  a,  the 

it  breathed  atmospheric  air,  and  was        ink-bag  in  place. 

*  All  are  familiar  with  "  cuttle-fish  bones,"  so  commonly  used  as  food  for 
canary  hirds.  The  substance,  it  is  well  to  observe,  is  not  a  "bone,"  nor  de- 
rived from  a  true  "  fish."  It  is  simply  the  rudimentary  shell  of  a  mollusk. 
The  cuttle-fish  of  our  own  shores  is  a  harmless  animal,  only  tensor  twelve 
inches  long,  but  the  one  frequenting  the  African  seas  attains  a  formidable  size. 
This  is  the  "devil-fish,"  so  graphically  described  by  Victor  Hugo.  Its  staring, 
glassy  eyes  strike  terror  to  beholders.  It  has  eight  huge,  muscular  arms,  many 
times  the  length  of  its  body,  with  which  it  holds  its  prey  in  a  grasp  so  tenacious 
that  the  arms  have  been  severed  before  they  would  yield. 

t  The  ornithorhynchus  or  water-mole  of  New  Holland  is  a  mammalian-furred 
quadruped  with  webbed  feet  and  the  bill  of  a  duck.  In  this  animal  the  Creator 
peems  to  have  repeated  the  curioii*  contrivance  originally  provided  for  the 
Ichthyosaur. 


174  THE     AGE      OF     REPTILES. 

thus  compelled  to  come  frequently  to  the  surface  of 
the  water.  Its  neck  was  short  and  thick,  its'  head 
large,  and  its  body  twenty  or  thirty  feet  long.  Its 
jaws  had  an  enormous  opening,  some  having  been 
found  with  160  teeth,  which  could  be  renewed  many 
times,  as  above  each  -tooth  was  always  the  bony  germ 
of  a  new  one.  The  eyes  were  often  two  feet  in  diam- 
eter. Surrounding  the  pupil  of  each  one  was  a  circu^ 
lar  series  of  thin  bony  plates.  This  apparatus,  which 
still  exists  in  the  eyes  of  turtles  and  lizards,  could  be 
used  to  increase  or  diminish  the  curvature  of  the  cornea, 
and  adapt  the  magnifying  power  to  the  wants  of  the 
animal.  The  eye  could  thus  be  used  as  a  telescope  or 
a  microscope  to  see  its  prey  far  and  near,  and  to  descry 
it  in  the  darkness  and  depths  of  the  sea.  The  fossil  ex- 
crements of  the  Ichthyosaur  are  styled  coprolites,  and 
when  polished  are  sold  as  jewelry.*  They  reveal  dis- 
tinctly the  food  and  the  internal  organism  of  this  Meso- 
zoic  saurian.  In  them  have  been  found  the  scales  and 
bones  of  smaller  animals  of  their  own  species.  The  quar- 
ries of  Lyme  Regis,  in  Dorsetshire,  England,  abound  in 
the  remains  of  the  Ichthyosaur.f 


*  Under  the  name  of  "beetle  stones"  coprolites  have  been  also  used  for 
artistic  purposes.  Dr.  Buckland,  the  celebrated  English  geologist,  had  a  table 
in  Iris  drawing-room  that  was  made  entirely  of  these  fossils,  and  was  often  much 
admired  by  persons  who  had  not  the  least  idea  of  what  they  were  looking  at. 
"  I  b,ave  seen,"  says  his  son,  "  in  actual  use,  ear-rings  made  of  the  polished 
portions  .of  coprolites  (for  they  are  as  hard  as  marble) ;  and  while  admiring 
the  beauty  of  the  wearer,  have  made  out  distinctly  the  scales  and  bones  of  the 
flsh  which  once  formed  the  dinner  of  a  hideous  reptile,  but  now  hung  pendulous 
from  the  ears  of  an  unconscious  belle,  who  had  evidently  never  read  or  heard  of 
such  productions."— Bucklantfs  Curiosities  of  Natural  History, 

t  In  1811,  Mary  Anning,  a  poor  country  girl,  who  made  her  precarious  living 
by  picking  up  fossils,  for  which  the  neighborhood  was  famous,  was  pursuing 
her  avocation,  hammer  in  hand,  when  she  perceived  some  bones  projecting  a 
little  out  of  the  cliff.  Finding,  ou  examination,  that  it  wae  part  of  a  large  skele- 


TRIASSIC    AND    JURASSIC    PERIODS.     177 

2.  The  Plesiosaur  had  the  head  of  a  lizard,  the  teeth  of 
a  crocodile,  the  neck  of  a  swan,  the  trunk  and  tail  of  a 
quadruped,  the  ribs  of  a  chameleon,*  and  the  paddles  of 

FIG.  81. 


A  Coprolite. 


ton,  she  cleared  away  the  rubbish,  and  found  the  whole  creature  imbedded  in 
the  block  of  stone.  She  hired  workmen  to  dig  out  the  block  of  lias  in  which  it 
was  buried.  In  this  manner  was  the  first  of  these  monsters  brought  to  light ;  a 
monster  some  thirty  feet  long,  with  jaws  nearly  a  fathom  in  length,  and  huge 
saucer  .eyes — which  have  since  been  found  so  perfect  that  the  petrified  lenses 
have  been  split  off  and  used  as  magnifiers. 

Hugh  Miller  gives  the  following  graphic  description  of  the  lias  of  Scotland : 
"It  consists  of  laminae  as  thin  as  sheets  of  pasteboard,  which,  of  course,  shows 
that  there  was  but  little  deposited  at  a  time,  and  pauses  between  each  deposit. 
Yet  never  did  characters  or  figures  lie  closer  on  a  printed  page  than  the  organ- 
isms on  the  surfaces  of  these  leaf-like  laminae.  We  insinuate  our  lever  into  a 
fissure,  and  turn  up  a  portion  of  one  of  the  laminae,  whose  surface  had  last  seen 
the  light  when  existing  as  part  of  the  bottom  of  the  old  Liassic  sea,  when  more 
than  half  of  the  formation  had  still  to  be  deposited.  The  ground  of  the  tablet  it' 
of  a  deep  black,  while  the  colors  of  the  fossils  stand  out  in  various  shades,  from, 
opaque  to  a  silvery  white  or  deep  gray.  There,  for  instance,  is  a  group  of  large 
ammonites,  as  if  drawn  in  white  chalk ;  there,  a  cluster  of  minute  bivalve 
shells,  each  of  which  bears  its  thin  film  of  silvery  nacre.  We  turn  over  another 
page.  Here  are  ammonites  of  various  sizes,  but  all  of  one  species,  as  if  a  whole 
argosy  had  been  wrecked  at  once  and  sent  to  the  bottom.  And  here  we  open 
yet  another  page,  which  bears  a  set  of  extremely  slender  belemnites.  They  lie 
along  and  athwart,  and  in  every  possible  angle,  like  a  heap  of  boarding-pikes 
thrown  carelessly  down  a  vessel's  deck  on  the  surrender  of  her  crew.  Here,  too, 
is  an  assemblage  of  bright,  black  plates,  that  shine  like  pieces  of  Japan  work, 
the  head-plates  of  some  fish  of  the  ganoid  order ;  and  here  an  immense  accumu- 
lation of  minute,  glittering  scales  of  a  circular  form.  And  so,  leaf  after  leaf,  for 
tens  and  hundreds  of  feet  together,  repeats  the  same  strange  story.  The  great 
Alexandrian  Library,  with  its  unsummed  tomes  of  ancient  literature,  the  accu- 
mulation of  long  ages,  was  but  a  poor  and  meager  collection,  scarce  less  puny  in 
bulk  than  recent  in  date,  when  compared  with  this  vast  and  wondrous  library  of 
the  lias  of  Scotland." 

*  Each  pair  of  ribs  surrounded  the  body  with  a  complete  girdle  formed  of  five 
piece?,  thus  affording  great  facility  for  the  expansion  and  dilation  of  the  lungs. 


178  THE     AGE     OF    REPTILES. 

a  whale.  Its  tail  was  shorter  than  that  of  the  ichthy* 
osaur,  being  only  sufficient  to  act  as  a  rudder  in  guiding 
the  body.  To  compensate  this  loss  and  assist  in  propul- 
sion, its  paddles  were  much  larger  and  more  powerful. 
Its  appearance  presented  a  striking  contrast  to  that  of  its 
more  ponderous  foe,  the  ichthyosaur,  whose  attacks  it 
could  escape  by  sinking  to  the  bottom,  while  its  long 
neck  reached  to  the  surface  of  the  wrater  and  maintained 
respiration. 

3.  The  Pterodactyle  (wing-fingered),  in  its  apparent 
monstrosity*  surpassed  even  the  two  reptiles  just  men- 
tioned. It  was  so  named  because  the  bone  of  one  finger 
was  greatly  expanded  in  order  to  support  an  extended 
membrane  for  flying  (Fig.  82).  It  was  a  true  aerial 
reptile.  Its  wings  resembled  those  of  bats.  Its  bones 
were  hollow,  like  those  of  birds,  but  it  bore  no  feathers, 
and  had  a  mouth  full  of  teeth.  Remains  have  been  found 
indicating  a  spread  of  wing  of  not  less  than  sixteen  feet ; 
but  the  usual  species  of  the  Liassic  did  not  exceed  ten 
inches  in  length.  Its  ordinary  position  was  upon  its 
hind  feet,  walking  uprightly  with  folded  wings,  or 
perched  on  trees>  or  climbing  along  cliffs  with  its  hooked 

*  The  fins  of  the  fishes  of  the  Devonian  seas  became  the  paddles  of  the  ichthy- 
osaur and  of  the  plesiosaur ;  these,  in  their  turn,  became  the  membranous  foot 
of  the  pterodactyle,  and,  finally,  the  wing  of  the  bird.  Afterwards  came  the 
articulated  fore-foot  of  the  terrestrial  mammalia,  which,  after  attaining  remark- 
able perfection  in  the  hand  of  the  ape,  became,  finally,  the  arm  and  hand  of  man, 
an  instrument  of  wonderful  delicacy  and  power,  belonging  to  an  enlightened 
being  gifted  with  the  divine  attribute  of  reason !  A  careful  examination  of  the 
fore  paddles  of  the  plesiosaur  reveals  all  the  essential  parts  of  the  human  arm— 
the  scapula,  humerus,  radius  and  ulna,  the  bones  of  the  carpus,  the  metacarpus 
and  the  phalanges.  Was  not  this  a  prophecy  of  man  ?  "  Let  us,  then,  dismiss 
this  idea  of  monstrosity,  which  can  only  mislead  us,  and  not  consider  antedilu- 
vian beings  as  mistakes  or  freaks  of  nature.  Let  us  not  regard  them  with  dis- 
gust ;  let  us  learn,  on  the  contrary,  to  behold  in  them  with  admiration  the  divine 
proofs  of  design  which  they  display,  and,  in  their  organization,  to  see  the  hand! 
work  of  the  sublime  Creator  of  all  things." 


.  (• 
> 


TRIASSIC    AND    JURASSIC    PERIODS.    181 

claws  and  feet.  The  smaller  ones  lived  on  insects,  but 
the  larger  probably  pounced  on  struggling  reptiles,  or, 
diving  into  the  water,  preyed  on  fish.  More  than  twenty 
species  of  the  pterodactyle  have  been  discovered  in  the 
old  world,  but  in  the  new  there  have  been  found  only  a 
pair  of  finger-bones,  at  Phosnixville,  Pa.  Poets  have  long 
pictured  to  us  a  flying  dragon  of  the  olden  time,  which 
played  a  conspicuous  part  in  pagan  mythology.  It 
breathed  fire,  poisoned  the  air  with  its  exhalations,  and 
disputed  with  man  the  possession  of  the  earth.  In  the 
Jurassic  times  we  find  the  realization  of  this  creature 
of  poetic  fancy,  but  it  is  only  an  uncouth  reptile,  utterly 
unworthy  of  those  fabled  conflicts  in  which  gods  and 
heroes  shared. 

4.  The  Dinosaurs  (terrible  lizards)  were  land  reptiles 
of  enormous  size  that  roamed  elephant-like  over  the 
river-plains,  or  browsed  in  the  forests  of  the  Oolitic  and 
Wealdcn  Epochs.  These  included  the  megalosatir  (large 
lizard),  hylteosaur  (wood-lizard),  iguanodon,  etc.  (Fig. 
83),  huge  monsters  from  forty  to  seventy  feet  in  length. 
The  megalosaur*  was  carnivorous,  having  teeth  curved 
backward  like  a  pruning-knife,  and  with  a  double  edge 
of  enamel  so  as  to  cut  like  a  sabre  equally  on  each  side. 
The  iguanodon f  (ig-wan-o-don)  was  herbivorous,  twigs  of 
cypress  having  been  found  fossil  in  its  stomach,  and 
its  teeth  often  being  half-worn  to  the  roots. 

*  A  thigh-bone  has  been  found  four  and  a  half  feet  long,  indicating  a  leg  eight 
or  nine  feet  in  length,  and  an  animal  taller  than  a  man  on  horseback. 

t  A  party  of  twenty-one  scientific  men,  at  tho  invitation  of  Dr.  Hawkins, 
once  took  dinner  within  the  restored  body  of  this  animal.  On  that  occasion 
Dr.  Owen,  the  celebrated  geologist,  sat  in  the  head  for  brains !  This  model 
contains  659  bushels  of  artificial  stone,  100  feet  of  iron  hooping,  600  bricks,  20 
feet  of  inch  bar  iron,  900  plain  tiles,  and  650  two-inch,  half-round  drain  tiles; 
while  the  legs  are  four  iron  columns,  nine  feet  long  and  four  inches  in  diam- 
eter. ("  Penny  Guide  to  the  Crystal  Palace  at  Sydcnham.") 


182  THE      AGE      OP     REPTILES. 


The  Megalosaur  and  Hylseosaur.    Restored  by  Hawkins. 

There  is  a  restoration  of  a  megalosaur  in  the  Crystal 
Palace  at  Sydenham,  England.  .This  model  was  con- 
structed under  the  direction  of  B.  Waterhouse  Hawkins. 
On  the  back  of  the  animal  is  a  hump  like  the  withers 
of  a  horse.  (See  p.  269.)  From  the  few  bones  discov- 
ered at  that  time,  this  celebrated  anatomist  decided  that., 
to  make  the  huge  head  effective,  a  mass  of  muscle  and 
bone  on  the  fore  shoulders  was  .essential.  This  bunch 
was  thought  by  other  geologists  to  be  a  mere  monstrosity 
of  his  own  invention.  Subsequently,  the  entire  skeleton 
being  found,  the  conclusion  was  proved  to  be  correct. 

5.  TJie  Labyrinthodon  was  a  frog-like  quadruped,  often 
attaining  the  size  of  an  ox.  It  is  so  named  because  the 
outer  coating  of  its  teeth  was  bent  inward  in  intricate 
mazy  folds.  Its  head  was  protected  by  a  helmet,  and  its 
body  by  a  scaly  armor. 

The  Rampliorhyncus,  the  remains  of  which  have 
been  found  in  the  quarries  of  Solenhofen,  is  a  curious 
intermediate  link  between  birds  and  reptiles.  Its  tail. 


TRIASSIC    AND    JURASSIC    PERIODS.       183 

a  singular  appendage  shown   in   the   figure,  was   long, 
reptile-like,  and  dragged  upon  tha  ground,  while  its  foot- 


Labyrinthodon  of  the  Trias  restored,  with  its  foot-prints 

prints  were  bird-like.    No  wonder  that  palaeontologists 
hesitate  whether  to  class  it  with  birds  or  with  reptiles. 

FIG.  85. 


The  Ramphorhyncus,  with  OOHtic  Vegetation 


184  THE     AGE      OF     REPTILES. 

Bird-tracks.— In  the  red  sandstones  of  the  Connecticut 
valley,  numerous  foot-prints  have  been  found,  described 

FIG.  86. 


Imprints  of  Feet.  Turner's  Falls,  Massachusetts. 


TRIASSIC    AND    JURASSIC    PERIODS.     185 

by  Hitchcock  as  jnainly  the  tracks  of  birds.  The 
number  of  these  foot-prints  is  wonderful.  Tracks  of 
many  different  sizes  and  species  often  traverse  the  same 
slab.  The  largest  tracks  are  fifteen  inches  long,  and 
so  deep  as  to  hold  nearly  two  quarts  of  water.  .They 
were  made  by  an  animal  walking  erect  and  having  a 
stride  of  three  feet.  Hitchcock  estimates  that  it  far  ex- 
ceeded the  ostrich  in  size,  being  at  least  twelve  feet  high, 
and  weighing  from  400  to  800  pounds.  From  the  fact 
that  parallel  rows  of  tracks  are  found,  we  infer  that  these 
strange  bipeds  frequented  in  flocks  the  shores  of  the  Con- 
necticut, and  waded  into  its  shallow  waters  in  quest  of 
the  fish  and  mollusks  of  the  Mesozoic  types,  now  long 
extinct.*  Geologists  are  divided  in  opinion  as  to  whether 
any  of  these  tracks  were  made  by  birds,  and  not  rather 
by  three-toed  reptiles  somewhat  similar  to  the  ramphor- 
hyncus.  (Fig.  85.) 


.—  /.  Climate.—  The  Gulf  Stream,  sweep- 
ing northward  through  the  center  of  the  continent, 
combined  with  the  other  causes  already  named  to 
ameliorate  the  climate  so  as  to  permit  a  sub-tropical 
growth  as  far  north  as  latitude  60°.  Corals  and  ammo- 
nites, now  restricted  to  torrid  seas,  then  flourished  in  the 


*  "It  is  a  solemn  and  impressive  thought  that  the  footprints  oi  these  dumb  and 
senseless  creatures  have  been  preserved  in  all  their  perfection  for  thousands  of 
ages,  while  so  many  of  the  works  cf  man  which  date  but  a  century  back  have 
been  obliterated  from  the  records  of  time.  Kings  and  conquerors  have  marched 
at  the  head  of  armies  across  continents,  and  piled  up  aggregates  of  human  suf- 
fering and  experience  to  the  heavens,  and  all  the  physical  traces  of  their  march 
have  totally  disappeared ;  but  the  solitary  biped  which  stalked  along  the  mar- 
gins of  a  New  England  inlet  before  the  human  race  was  born,  pressed  footprints 
in  the  soft  and  shifting  sand  which  tho  rising  and  sinking  of  the  continent  could 
not  wipe  out."—  Winchell. 


186  THE     AGE     OF    REPTILES. 

valley  of  the  Upper  Mississippi,  while  .the  prairies  of  Ohio 
and  Illinois  were  green  with  perennial  palms  and  pines. 

2.  Salt  3?eds . — The  most  extensive  salt  deposits  in 
Europe  are  of  the  Triassic  Period,  and  it  has  hence  been 
sometimes  styled  the  Saliferous  formation.     In  Cheshire, 
England,  are  two  beds  of  rock  salt,  each  nearly  100  feet 
thick.    At  Cordova,  Spain,  is  a  mountain  of  salt  several 
hundred  feet  high.     This  salt  rock  is  pure  as  glass,  and  is 
carved  into  images,  cups,  etc.,  for  sale  to  travelers.    At 
the  base  is  a  brook,  which  in  rainy  seasons  swells  into  a 
river,  and  carries  down  so  much  salt  as  to  destroy  the 
fish.*     The  mines  of  Cracow,  Poland,  have  been  worked 
at  a  depth  of  over   1,000   feet  in  galleries  whose  total 
length  is  270  miles.    At  one  point  is  a  village  with 
streets  and  houses,  and  even  a  chapel  with  altar,  pulpit, 
statues,  etc.,  all  hewn  out  of  the  solid  rock.     The  deposits 
in  the  salt  beds  indicate  that  .the  same  conditions  existed 
in  portions  of  Europe  during  the  Triassic  as  in  New 
York  during  the  Salina  Period. 

3.  T/ie   Gold-bearing  flocks  of  California 

are  mainly  Jurassic  or  Triassic  metamorphic  sandstones, 
with  interstratified  quartz  containing  gold.  Where  the 
quartz  veins  have  come  to  the  surface  and  weathered,  the 
particles  of  gold  have  been  washed  out,  and  thus  formed 
the  auriferous  sands.  There  are  frequent  dikes  of  trap 
and  outcrops  of  granite.  On  the  crests  of  the  Sierra 
Nevada  these  masses  of  granite  often  assume  a  dome 


*  This  mountain  presents  a  wondrous  beauty  to  the  looker-on  at  sunrise. 
Aside  from  its  graceful -and  majestic  form,  it  seems  to  rise  above  the  river  like  a 
mountain  of  precious  gems,  displaying  the  brilliant  colors  of  the  rainbow. 


THE     CRETACEOUS    PERIOD.  187 

shape,  and  reach  a  height  of  15,000  feet  above  'the  sea- 
level. 

£.  ^Disturbances  '.  —  Long-continued  upheavals  and 
perhaps  even  terrific  convulsions  attended  the  close  of 
this  era,  whereby  such  stupendous  mountain  ranges  as 
the  Sierra  Nevada,  Sierra  Madre,  etc.,  were  lifted  above 
the  interior  sea.  The  trap  rocks  of  Mts.  Holyoke  and 
Torn,  East  and  West  Eocks  near  New  Haven,  Conn., 
the  Palisades  on  the  Hudson,  and  Bergen  Hill  in  New 
Jersey,  are  all  illustrations  of  the  wide  extent  of  the 
igneous  action.  Everywhere  trap  dikes  and  ridges  at- 
tend this  formation.  The  proofs  that  the  trap  was 
thrown  out  in  a  melted  state  are  abundant.  The  adja- 
cent sandstone  has  been  baked  by  the  heat,  the  layers 
uplifted  by  the  escaping  steam,  and  the  fissures  often 
filled  with  crystallized  minerals. 

C  RETACEO  US    PERIOD. 


.  —  The  Cretaceous  rocks  occur  on  the  At- 
lantic coast  from  New  York  to  South  Carolina,  along 
the  Gulf  through  Texas,  and  northward  over  the  slopes 
of  the  Eocky  Mountains,  at  a  height  of  6,000  feet  above 
the  sea,  through  Colorado  to  the  head-  water  of  the  Mis- 
sissippi river.  (See  Frontispiece). 

Kinds  of  32oc£.—ThQ  name  is  derived  from  the 
Latin  creta,  chalk.  The  famous  white  chalk  cliffs  of 
Dover  are  of  this*  formation.  On  our  continent  this 
group  contains  no  chalk.  The  beds  consist  of  layers  of 
sand  of  various  colors  —  white,  green,  or  red,  and  are  often 


188 


THE     AGE     OF    REPTILES. 


FIG.  87. 


BO  loose  that  they  may  be  rubbed  to  pieces  with  the  hand 
or  dug  with  a  spade.  Beds  of  "  green  sand  "  are  abundant 
in  New  Jersey.  This 
is  composed  of  small 
rounded  grains,  con- 
sisting mostly  of  sili- 
cate of  iron  and  potash: 
The  peculiar  shape  of 
these  granules  is  prob- 
ably due  to  the  fact 
that  they  are  the  casts 
of  microscopic  shells. 
It  is  termed  marl,  and 
is  extensively  used  for 
fertilizing  purposes.  In 

A  common  Fossil  of  the  Green  Sand — the  Exo- 

western  Texas  are  beds  gyracostata. 

of  cream-colored  lime- 
stone called  "  Chimney  Stone,"  from  its  use  in  building 
chimneys.  When  taken  from  the  quarry,  it  is  soft 
enough  to  hew  with  an  axe  or  smooth  with  a  plane. 
The  Cretaceous  beds  of  the  west  contain  many  valuable 
seams  of  coal,  such  as  the  deposits  of  Mt.  Diablo,  near 
San  Francisco,  of  Bellingham  Bay,  Washington  Terri- 
tory, etc.  The  quicksilver  mines  of  New  Almaden  are 
also  referred  to  this  period. 

Fossils .  — CHALK. — If  we  examine  chalk  with  a  pow- 
erful microscope,  we  shall  find  that  it  is  composed  of  the 
remains  of  numerous  zoophites,  of  various  kinds  of 
minute  shells,  and  above  all  of  rhizopods*  (foramenif- 

*  The  imagination  fails  to  conceive  the  countless  millions  of  these  foramenif- 
era  in  all  ages.  In  Nature  nothing  is  small.  She  seems  to  have  delighted  in 
achieving  the  grandest  results  with  the  feeblest  means.  The  history  of  this  ani- 


TH  E     C  R  E  TA  C  E  0  US     PERIOD. 


189 


era),  so  tiny  that  their  very  smallness   seems   to   have 
rendered  them  indestructible.      Eighteen    hundred    of 


FIG.  88. 


Chalk  of  Gravesend  (Ehrenberg). 


these  placed  in  a  row  would  occupy  but  an  inch  of 
space.  Schleiden  says  that  the  chalk  on  a  visiting  card 

malcule  is  a  striking  illustration  of  this  truth.  A  handful  of  sand  taken  up  on 
the  sea-shore  is  often  half  composed  of  these  microscopic  shells.  The  Paris 
chalk  contains  them  so  abundantly  that  D'Orbigny  found  58,000  in  a  cubic  inch  of 
the  rock.  Paris  itself  is  built  up  of  these  cast-off  abodes  of  the  tiny  rhizopod. 
The  species  vary  in  different  sections  and  ages.  A  curious  application  of  this 
has  lately  come  to  notice.  Ehrenberg  was  requested  to  assist  in  tracing  the 
robbery  of  a  case  of  wine.  It  had  been  repacked  by  the  criminal  in  sand  differ- 
ing from  that  in  the  original  case.  Ehrenberg,  by  a  microscopic  analysis,  deter- 
mined that  the  sand  was  found  only  on  a  certain  ancient  sea-coast  in  Germany. 
On  this  fact  being  discovered,  the  locality  of  the  crime  was  speedily  found  and 
the  thief  arrested. 


190  THE     AGE     OF    REPTILES. 

is  a  microscopic  cabinet  of  a  hundred  thousand  shells* 
Throughout  the  beds  of  chalk  are  scattered  nodules  of 
flint,  which,  being  broken,  reveal  at  the  center  shells, 
corals,  etc.,  the  nuclei  around  which  the  flint  collected 
out  of  the  chalk  before  that  had  consolidated  from  the 
pasty  mass  in  which  it  first  formed  on  the  sea-bottom. 

DEEP  SEA  DREDGINGS. — The  soundings  made  in 
1857-8  along  the  great  telegraphic  plateau  which  reaches 
fromValentia  Bay  to  Newfoundland  show  that  the  sea- 
bottom  is  covered  with  a  fine  calcareous  mud.  Micro- 
scopic examination  proved  this  to  consist  of  shells  of 
rhizopods  and  other  species  allied  to  the  Cretaceous 
Period.  These  fragile  and  delicate  shells  were  found  to 
be  in  a  perfect  state  of  preservation.  Many  similar  dis- 
coveries have  since  been  made  in  different  parts  of  the 
ocean.  Depths  of  the  sea  so  profound  that  the  highest 
peaks  of  the  Eocky  or  the  Himalaya  Mountains  could  be 
engulfed  within  them  are  believed  to  be  inhabited  by 
organic  forms  which  have  undergone  little  if  any  change 
since  the  Mesozoic  Age. 

THE  AMERICAN  FOSSILS  are  far  removed  from  the 
microscopic  remains  of  the  Old  World.  While  chalk- 
beds  were  accumulating  on  the  deep-sea  bottom  in  Eu- 
rope, the  shallow  waters  on  the  American  shore  teemed 
with  as  busy  and  strange  a  life  as  swarmed  upon  the 
coasts  of  England,  France  or  Germany  during  the  entire 
Mesozoic  Age.  The  Cretaceous  beds  of  New  Jersey  have 
furnished  abundant  reptilian  remains.* 

1.  The  Cimoliasaur  and  the  Elasmosaur  were  huge 


*  We  are  indebted  to  the  untiring  and  skilful  labors  of  Dr.  Cope  and  Dr.  Leidy, 
of  Philadelphia,  for  the  following  description  of  these  Cretaceous  reptiles. 


THE     CRETACEOUS     PERIOD.  191 

eea-serpents,  twenty-five  to  forty  feet  long,  with  bodies 
larger  than  an  ox,  sharp  teeth,  and  flippers  like  a  whale, 
— the  latter  having  a  flattened  tail,  which  it  used  like  an 
oar  for  sculling. 

</'  2.  The  Mosasaur  was  a  whale-like,  carnivorous  mon- 
ster, shorter  and  stouter  than  the  preceding  reptiles.  Its 
ponderous  bones  are  wrecked  along  the  old  sea-coast,  and 
may  be  seen  on  the  Alabama  river  projecting  from  the 
limestone  cliffs. 

3.  Snapping-turtles,  six  feet  long  and  of  many  varieties, 
lived  in  the  salt  water,  as  the  now  living  species  do  in 
fresh  water. 

4.  Crocodiles  were  exceedingly  abundant.   Three-fourths 
of  all  the  bones  found  in  the  marl-pits  are  those  of  the 
crocodile.    These  creatures  swarmed  along  what  is  now 
the  river-front  of  Philadelphia,  and  peopled  every  pool 
and  lagoon  on  the  ancient  shores  of  Pennsylvania.    Most 
obstinate  combats  must  have  taken  place  between  these 
fierce  crocodiles  and  the  great  snapping- turtles  which 
inhabited  the  same  waters. 

4.  The   Dinosaurs  rivaled  in  size  the  elephants  of  our 
day.     Their  aspect  was  strange  and  portentous;   some 
chiefly  squatted,  some  leaped  on  their  hind  limbs  like  the 
kangaroo,  and  some  stalked  on  erect  legs  like  great  birds, 
with  small  arms  hanging  uselessly  by  their  sides,  as  with 
bony  visage  they  surveyed  land  and  water  from  their 
lofty  elevation. 

5.  The  Hadrosaur  was  a  massive,  herbivorous  reptile 
about  thirty  feet  long.     The   fossil  remains  have  been 
lately  restored  by  Hawkins,  and  are  set  up  in  the  Mu- 
seum of  Natural  Sciences,  Philadelphia.    This  monster 
doubtless  walked   mainly   on   its   hind   legs,  its   knees 


192  THE      AGE      OF     REPTILES. 

thrown  upward  and  forward,  and  its  huge  tail  trailing 
behind.  Its  expression  was  that  of  a  perpetual  grin,  as 
its  open  mouth  revealed  several  rows  of  shiny  teeth 
with  which  it  cut  the  twigs  on  which  it  fed. 

6.  The  Lcdaps  was  a  powerful,  carnivorous  animal, 
and  the  destructive  enemy  of  the  preceding  smaller  rep- 
tiles. A  full-grown  specimen  was  probably  twenty-three 
feet  in  length.  Its  toes  were  long  and  slender  like  those 
of  a  bird  of  prey.  They  were  armed  with  flattened, 
hooked  claws,  ten  to  twelve  inches  long,  and  adapted  to 
grabbing  and  tearing.  Its  teeth  were  curved,  knife- 
shape,  saw-edged,  and  fitted  like  scissors  for  cutting. 
The  tail  was  long,  rounded,  and  strong,  and  capable  of 
striking  a  blow  or  of  throwing  an  enemy  within  reach 
of  the  kick  or  grab  of  the  terrible  hind  leg.  It  could 
leap  like  the  kangaroo,  and  probably  captured  its  prey  by 
a  few  immense  bounds. 

SCENIC  DESCRIPTION*— Let  us  picture  to  our- 
selves  a  landscape  in  this  Mesozoic  Age.  It  is  an  arm  of 
the  ocean  with  broad,  flat,  muddy  shores,  at  the  bottom 
of  which  is  slowly  gathering  a  sandy  rock.  The  fog  has 
just  lifted,  and  discloses  a  view  of  surpassing  beauty.  On 
either  hand  the  summits  of  the  hills  are  crowned  with 
lordly  pines,  while  the  sloping  land  is  overgrown  with 
palms  and  tropical  trees.  The  shore  is  green  with  ferns 
and  reeds,  whose  tufted  tassels  nod  in  the  gentle  breeze. 
No  grass  carpets  the  plain,  no  flowers  embellish  the 
scene,  no  birds  sing  in  the  trees.  It  is  the  reign  of 
reptiles.  On  every  hand  they  swarm — crawling,  hopping, 
stalking  by  the  shore.  The  water  is  alive  with  them— 
swimming,  diving,  and  filling  the  air  with  an  indescrib- 


T  II  E      C  R  E  T  A  C  E  O  US      PERIOD.  193 

able  din.  All  daylong  enormous  lizards  crawl  through 
the  forests,  crushing  the  reed-like  trees  before  them  in 
their  headlong  course,  or  plunge  into  the  sea,  leaving 
behind  a  broad  wake  like  a  steamer ;  while  others,  more 
fearful  still,  spread  their  wings  and  riot  in  the  air.  Sail- 
ing in  and  out  among  the  shallow  coves  and  bays  of 
the  coast,  the  plesiosaur,  arching  its  long  neck,  eagerly 
watches  a  shoal  of  fish  swimming  near.  But  with  quick 
sharp  strokes  of  its  whale-like  paddles,  the  huge  ichthyo- 
saur  darts  into  view,  and  glares  upon  its  prey  with  its 
great  bulging  eye.  Instantly  the  swan  neck  disappears 
under  the  water,  and  the  plesiosaur  is  hidden  from  its 
rapacious  foe — the  terror  of  the  Mesozoic  seas.  Mighty 
dinosaurs,  rivaling  the  elephant  in  size,  stalk  along  the 
shore  or  squat  on  the  beach  stupidly  gazing  on  the  scene, 
save  when  the  kelaps,  with  fearful  bounds,  leaps  among 
their  frightened  herds,  and  tears  them  with  his  eagle- 
claws.  But  night  draws  on  apace.  In  the  dim  recesses 
of  the  woods  the  pterodactyle — that  winged  dragon  so 
terrible  to  behold — sails  slowly  along  on  its  broad,  leath- 
ern wings.  As  the  shadows  deepen,  mighty  sea-ser- 
pents dart  to-and-fro,  battling  with  the  rising  billows; 
that  huge  bloated  frog — the  labyrinthodon — jumps  by 
with  great  ungainly  hops,  while  a  tiny  mammal,*  the 
first  of  its  kind,  flies  frightened  to  the  shelter  of  the 
woods. 


*  This  was  th  3  Dromatherium  Sylvestre,  the  jaw-bone  of  which  was  discov- 
ered by  Emmons  in  North  Carolina.  It  is  the  only  mammal  yet  known  to  have 
existed  in  America  during  the  Mesozoic  Age.  In  Europe,  two  or  three  insigni- 
ficant ones  of  the  lowest  order  have  been  discovered.  No  true  bird  remains 
have  been  found  on  thin  continent,  but  in  the  quarries  of  Solenhofen  they  have 
been  scantily  preserved.  One,  called  the  Archseopterys,  and  Bird  of  Solen- 
hofen. is  very  clearly  identified,  except  the  head. 


194  THE     AGE      OF     MA  MM  A  L  8. 

M^esozoic  ^Disturbances . — The  Mesozoic  Time, 
like  the  Palaeozoic,  was  closed  by  mighty  upheavals.  As 
"Winchell  beautifully  says:  "The  ever-shrinking  earth- 
nucleus  necessitated  the  ever-enlarging  wrinkles  of  the 
enveloping  crust ;  the  furrows  must  deepen  and  the  folds 
must  rise."  The  increasing  pressure  of  the  Atlantic  and 
Pacific  oceans  produced  another  upheaval  of  the  land, 
and  another  addition  to  the  growing  continent.  This 
was  probably  not  a  sudden  convulsion,  but  a  long-con- 
tinued upward  movement.  By  it,  however,  the  condi- 
tions of  life  were  changed.  All  the  Mesozoic  types  dis- 
appeared— not  a  species  survived  the  catastrophe.  A  few 
mammals,  birds  and  flowering  plants,  types  prophetic  of 
the  Cenozoic  Time,  had  appeared,  but  they  all  went  down 
in  the  shock. — Another  cycle  of  geologic  history  is  fin- 
ished, another  phase  of  life  has  swept  across  the  slowly- 
forming  world,  culminated  and  broken  on  the  shore  of 
the  past.  The  reign  of  reptiles  is  closed. 


•CENOZOIC      §  I  M  E. 

The  Cenozoic  or  recent  life  of  geologic  history  com- 
prises only  one  age,  that  of  mammals. 

AGE  or  MAMMALS.  {  '•  TertiaT  Period- 

(  2,  Post-Tertiary  Period. 

General  Characteristics.  —  The  more  striking 
scenes  of  life  hitherto  have  been  confined  to  the  water ; 
they  are  now  transferred  to  the  land.  Extensive  bodies 
of  fresh  water  teem  with  fishes  resembling  pickerel, 


THE     AGE     OF    MAMMALS. 


195 


perch,  eels,  etc.  Molluscan  life  takes  on  the  types  of 
modern  times— the  bivalves  increasing  and  the  gastero- 
pods  taking  the  lead.  Insects  throng  every  element — 
earth,  air  and  water.  Birds  are  also  found  in  greater 
numbers.  It  is  emphatically,  however,  the  age  of  mam- 
mals. Quadrupeds  of  enormous  bulk— many  identical 
with  existing  species — occupy  the  land.  The  herbs, 
shrubs  and  trees — the  flowers,  fruits  and  grains — all  that 
can  gladden  the  senses  or  satisfy  the  wants  of  man — 
appear  and  confirm  the  harmony  that  always  exists  be- 
tween organic  and  inorganic  nature. 

FIG.  89. 


Map  of  Tertiary  Period. 


196  THE     A  O  E     OF    MA  MM  A  L  S. 

Geography. — The  great  Mesozoic  upheaval  burst 
asunder  the  Gulf  Stream,  which  had  sent  the  warm 
waters  of  the  tropics  to  the  Arctic  Ocean.  On  the  south- 
west it  retired  to  nearly  its  present  limits,  but  a  long  arm 
reached  up  the  Mississippi  valley  to  the  mouth  of  the 
Ohio  river  (Fig.  89).  On  the  north  it  broadened  into 
the  great  Tertiary  Sea  which  extended  through  Nebraska 
and  the  western  part  of  Dacotah.*  The  Pacific  Ocean 
still  held  possession  of  the  western  coast,  while  the 
Atlantic  Ocean  covered  the  southeastern  border  of  the 
continent,  and  the  coral  b'uilders  were  yet  at  work  upon 
Florida. 

TERTIARY    PERIOD. 

i.  Claiborne  (Alabama)  Epoch. 

TERTiARYf  PERIOD.  J  2-  Jackson  (Mississippi)  Epoch. 

3.  Vicksburg  (Mississippi)  Epoch. 

4.  Yorktown  (Virginia)  Epoch. 

In  Europe,  the  divisions  of  the  Tertiary  Period  are 
Eocene  (recent  dawn),  Miocene  (less  recent),  and  Pliocene 

*  At  the  close  of  the  Mesozoic  Age,  Europe  was  still  far  from  displaying  the 
configuration  which  it  now  presents.  A  map  of  the  period  would  represent  the 
great  basin  of  Paris  (with  the  exception  of  a  zone  of  chalk),  the  whole  of  Switzer- 
land, the  greater'part  of  Spain  and  Italy,  the  whole  of  Belgium,  Holland,  Prussia, 
Hungary,  Wallachia,  and  northern  Russia,  as  one  vast  sheet  of  water.  A  band 
of  Jurassic  rocks  still  connected  France  and  England  at  Cherbourg.  This  dis- 
appeared at  a  later  period,  and  caused  the  separation  of  the  British  Islands  from 
what  is  now  France. — Figuier. 

t  The  name  Tertiary  is  a  relic  of  early  geological  science.  When  introduced, 
it  was  preceded  in  the  system  of  history  by  Primary  and  Secondary.  The  first 
of  these  terms  was  thrown  out  when  the  crystalline  rocks,  so  called,  were 
proved  to  belong  to  no  particular  age,  though  not  without  an  ineffectual  attempt 
to  substitute  it  for  Palaeozoic ;  and  the  second,  after  use  for  a  while  under  a  re- 
stricted signification,  has  given  way  to  Mesozoic.  Tertiary  holds  its  place 
simply  because  of  the  convenience  of  continuing  an  accepted  name  (Dana). 
The  term  Quaternary,  used  in  connection  with  the  Post-Tertiary  Period,  had  a 
similar  origin. 


THE     TERTIARY    PERIOD.  197 

(more  recent).  On  this  continent  these  terms  do  not 
apply,  and  an  American  classification  has  been  adopted. 
In  the  Pliocene,  most  of  the  species  are  allied  to  existing 
forms;  in  the  Miocene,  fewer  are  thus  related;  and  in 
the  Eocene,  we  recognize  only  the  dawn  of  modern  forms, 
The  Claiborne,  Jackson,  and  Vicksburg  beds  have  been 
referred  to  the  Eocene,  the  Yorktown  to  the  Miocene, 
and  the  Su  niter  and  Darlington  divisions,  recognized  by 
some  authorities,  to  the  Pliocene. 

I;0catio?i.  —  The  Marine,  Tertiary  beds  lie  on  the 
Atlantic,  Pacific,  and  Gulf  borders,*  and  extend  up  the 
Mississippi  valley  to  the  mouth  of  the  Ohio  river.  Fresh 
•water  Tertiary  beds  occur  on  the  eastern  slopes  of  the 
Eocky  Mountains  and  in  the  upper  Missouri  region. 
There  are  no  great  continental  strata,  as  in  the  Silurian 
Age,  but  rather  such  a  diversity  as  we  find  in  formations 
now  in  progress  on  the  sea-coast,  where  the  beds  often 
change  in  character  within  small  distances.  These 
modern  deposits  give  us  the  key  to  the  ancient  ones. 
(See  pp.  23  and  29.) 


*"  What  are  known  as  the  Pine  Barrens,  in  the  southern  States,  is  a  belt  of 
country  more  than  1,700  miles  long,  and  often  170  miles  broad,  stretching  from 
Richmond,  along  the  Atlantic  and  Gulf  coasts,  to  beyond  the  western  line  of 
Louisiana,  where  the  soil,  derived  from  the  decomposition  of  the  newest 
member  of  the  Tertiary  series,  is  sandy,  and  where  the  principal  arborescent 
form  is  the  long-leaf  pine.  It  is  emphatically  the  "poor  man's  region/'  These 
forests,  while  affording  a  valuable  article  of  lumber,  also  yield  pitch,  tar,  and 
turpentine.  On  the  Pacific  slope  the  Tertiary  rocks,  which  are  referred  to  the 
Miocene  Group,  appear  to  be  coterminous  with  the  Cretaceous.  They  enter  into 
the  frame-work  of  the  Coast  Ranges,  stretching  from  the  Columbia  to  San  Louis 
Bay,  and  probably  to  Cape  St.  Lucas;  and  throughout  the  entire  extent  the 
strata  are  upheaved,  plicated,  and  metamorphosed,  and,  at  frequent  intervals, 
invaded  by  igneous  products.  They  repose  in  horizontal  strata  upon  the  foot- 
hills of  the  Siorra,  but  are  in  a  disturbed  position  where  they  fold  around 
Shasta'.—  Foster's  Mississippi  Valley,  published  by  Messrs,  S.  C.  Qriggs  &  Co., 
Chicago. 


198  THE     AGE      OF     MAMMALS. 

tx- 

Kinds  of  3tock.  —  The  Tertiary  beds  consist  of 
sand,  clay,  marl,  pebbles,  etc.  There  are,  however,  valu- 
able buhrstones,  shell-rocks,  limestones,  and,  near  San 
Francisco,  slates  and  sandstones,  hardly  distinguishable 
from  more  ancient  formations. 

The  Eocene  of  the  old  world  contains  strata  of  NUM- 
MULITIC  (nummus,  a  piece  of  money)  limestone  thousands 
of  miles  in  length  and  hundreds  of  feet  in  thickness.  It 
is  so  called  because  it  is  largely  composed  of  a  fossil* 
having  the  shape  of  a  coin.  The  most  noted  Pyramids 
are  built  of  this  stone,  and  wagon-loads  of  the  fossils,  dis- 
integrated by  the  weather,  lie  at  their  base. 

Extensive  beds  of  light  bituminous  coal  (lignite)  are 
found  scattered  from  Pike's  Peak  to  the  Arctic  Ocean, 

across  the  treeless  regions 
FIG.  90.  west  of  the  Missouri,  and 

thence  into  Oregon.  The 
wide  distribution  and  con- 
venient locality  of  these 
Tertiary  coals  must  ex- 
ercise a  vast  influence  •  in 
facilitating  communica- 

Rhizopods  (Nummulites  ataica).  tionS  OVCr  the  great  deserts 

of  the  west,  and  can  but 

be  considered  as  a  providential  forecast  of  the  wants 
of  man. 

Fossils.— -I.  PLAKTS.— The  abundance  of  vegetable 
remains  proves  the  land  to  have  been  covered  with  an 
exuberant  flora.  Leaves  of  oak,  maple,  poplar,  hickory, 

*  The  nummulite  is  a  rhizopod,  being  the  giant  of  that  family.    (See  p.  100.)' 


THE      TERTIARY     PERIOD.  199 

cinnamon,  fig,  palm,  and  pine  are  abundant.*  A  leaf  of  a 
fan-palm  has  been  found  on  the  Upper  Missouri,  that, 
when  entire,  was  probably  twelve  feet  across  (Dana). 
Nuts  are  common  in  some  localities,  as  at  Brandon,  Vt. 
In  the  London  basin  a  single  collector  gathered  25,000 
specimens  of  fossil  fruits  representing  five  or  six  hundred 
species.  Many  of  them  were  products  of  aromatic  and 
spice  groves,  such  as  now  flourish  in  Ceylon  and  the  West 
Indies.  The  extensive  deposits  of  diatoms  at  Kichmond, 
Va.,  and  Bilin,  Germany,  etc.,  which  have  been  already 
mentioned  (page  48)  are  of  this  period. 

II.  ANIMALS. — Tertiary  shells  of  over  3,000  species  have 
been  found  in  America.  They  have  the  look  and  often- 
times the  freshness  of  modern  specimens,  as  may  be  seen 
in  the  accompanying  cuts  of  Miocene  Gasteropods.  (See 
Fig.  91.)  In  Colorado  and  Utah  are  shales  containing 
insects  so  well  preserved  that  even  the  microscopic  hairs 
of  the  wings  can  be  detected  (Denton).  The  first  bee 
made  its  appearance  in  the  amber  f  of  the  Eocene,  locked 


*  The  earth  had  already  its  seasons,  its  spring  and  summer,  its  autumn  and 
winter,  its  seed-time  and  harvest,  though  neither  sower  nor  reaper  was  there ; 
the  forests  then,  as  now,  dropped  their  thick  carpet  of  leaves  upon  the  ground  in 
the  autumn,  and  in  many  localities  they  remain  where  they  originally  fell,  with  a 
layer  of  soil  between  the  successive  layers  of  leaves — a  leafy  chronology,  as  it 
were,  by  which  we  read  the  passage  of  the  years  which  divided  these  deposits 
from  each  other.  Where  the  leaves  have  fallen  singly  on  a  clayey  soil  favorable 
for  receiving  such  impressions,  they  have  daguerreotyped  themselves  with  the 
most  wonderful  accuracy ;  and  the  trees  of  the  Tertiaries  are  as  well  known  to 
us  as  are  those  of  ojir  own  time.— Agassiz  in  Geological  Sketches. 

t  See  Fourteen  Weeks  in  Chemistry,  page  195.  Amber  has  been  found  quite 
jibundant  on  the  shores  of  the  Baltic,  washed  out  of  the  lignite  beds  by  the 
waves.  Species  of  coniferous  trees  existed,  from  which  gum  or  resin  flowed, 
and  becoming  fossilized,  amber  was  the  result.  In  flowing  down  the  tree,  in- 
sects, spiders,  small  crustaceans,  and  leaves  were  covered ;  and  thus  we  find 
them  preserved  in  the  transparent  amber.  Over  800  species  of  insects,  and  98 
of  trees  and  shrubs  have  been  observed,  besides  numerous  mosses,  fungi,  and 
liverwort. — Denton  in  Our  Planet. 


FIG/  91,  GASTEROPODS    OF    THE    MIOCENE. 


Pyrula  reticulala. 


Cancellana  rcticu!ata. 


Fusus  exilis. 


FIG.  92.     GASTEROPODS  OF  THE  MIOCENE. 


Murex  globosa.     (Half  natural  size.)  .          Galeodia  Hodgii. 

FIG.  93.    ECHINODERMS  OF  THE  MIOCENE. 


Rosette,  beneath. 

FIG.  04. 


Goniodypeus  subangulatus,  E. 

FIG.  95. 


Scutella  Newbernensis,  E. 
The  "  Lcne  Star  of  Texas. 


. 


Echinus  Ruffini. 


THE     AGE      OF     MAMMALS. 


96. 


up  hermetically  in  its  gum-lijke  covering — "  an  embalmed 
corpse  in  a  crystal  coffin,"  as  Hugh  Miller  quaintly  re- 
marks. Broken  wings  of  butterflies 
also  attest  the  presence  of  flowers. 
Ants,  crickets,  grasshoppers,  beetles, 
and  dragon-flies  are. so  numerous  that 
some  kinds  seem  to  have  afforded  food 
to  the  first  mammals  that  appeared. 
Fish  existed  in  great  abundance, 
mostly  allied  to  the  modern  perch 
and  salmon.  Sharks'  teeth  have  been 
>j  found  six  inches  in  length. 

The  bones  of  a  species  of  whale 
the  Zeuglodon  (yoke-tooth),  so 
called  from  the  shape  of  its  teeth, 
occur  in  great  abundance  scattered  over  the  cotton  lands 
of  the  south.  In  Alabama  they  have  been  laid  up  in 


Zeuglodon's  Tooth. 


THE      TERTIARY     PERIOD. 


walls  for  fences,  or  burned  for  lime.  A  single  vertebra  is 
a  load  for  a  man  to  carry.  The  animal  was  about 
seventy  feet  long.* 

QUADRUPEDS,  thick-skinned  and  ruminating  mammals, 
were  the  great  feature  of  the  Tertiary  life. 

European  Quadrupeds. — Cuvier  was  the  first  to  bring 
to  light  the  forms  of  these  long-extinct  animals.  In  the 
Gypsum  quarries,  near  Paris,  bones  were  dug  up  in  great 

FIG.  98. '  •• 


/&6>ir™ 


Scene  in  Paris  Basin. 
x.  The  Paleotherium.     2.  The  Anoplotherium.    3.  The  Xiphodon. 

numbers,  but  they  were  disregarded,  as  they  were  thought 
to  be  those  of  existing  species,  until  the  attention  of  this 
great  naturalist  was  directed  to  them.  He  gathered  a 
large  quantity  in  a  room,  and  commenced  the  work  of 
assorting  and  re-creating.  "At  the  voice  of  comparative 
anatomy  every  bone  and  fragment  resumed  its  place." 


*  The  restored  skeleton  of  a  Zeuglodon  is  on  exhibition  in  Wood's  Museum, 
Chicago.  It  contains  118  vertebrae,  and  its  head  is  six  feet  long.  Prof.  Winchell 
pronounces  it,  for  the  most  part,  an  accurate  representation  of  this  alligator-like 
whale. 


204  THE      ACE      OF     MA  M  M  A  L  S. 

(Cuvier.)     He  restored  the  animals,  assigned  them  to 
their  classes,  and  investigated  their  habits. 

The  neighborhood  seems  to  have  been  a  gulf  of  the  sea, 
into  which  emptied  several  rivers.  Animals  inhabiting 
the  banks  of  these  streams  Tere  borne  down,  and  de 

FIG.  99. 


View  of  the  Bad  Lands. 


••" 


.' 


posited  in  the  sediment  which  gathered  at  the  mouth. 
Among  the  quadrupeds  the   most  conspicuous  was  the  ' 
PdleotUerium  (ancient  wild   beast),   peaceful   flocks  of 
which  must  have  inhabited  the  plateau  which  environed 
the  ancient  basin   of   Paris.      It  resembled  the   South   - 
American  tapir,  but  was  as  large  as  a  horse. 

American  Quadrupeds. — On  this  continent  similar  dis-,v 
coveries  have  been  made  in  the  Mauvaises  Terres,  or  Bad 
Lands  of  Dacotah.     This  region  consists  of  immense  beds 
of  clay  cut  out  by  rivers  into  winding  channels,  leaving 


THE      TERTI'ARY     PERIOD.  205 

thousands  of  irregular  columnar  masses  often  one  to  two 
hundred  feet  in  height.  So  thickly  is  the  surface  studded 
with  these  natural  towers,  that  the  traveler  must  thread 
his  way  through  deep,  confined  labyrinthine  passages  not 
unlike  the  narrow,  irregular  streets  and  lanes  of  some 
quaint  old  European  town.*  The  soil  is  barren  and  arid, 
It  is  a  literal  Golgotha — a  place  of  bones.  At  every  step 
in  this  charnel-house  the  explorer  treads  upon  the  re- 
mains of  a  former  age.  The  clayey  walls  are  built  up 
with  broken  skeletons.  Hundreds  of  fossil  turtles  (see 
Fig.  100)  are  strewn  about,  many  weighing  a  ton  each. 
On  every  side  are  scattered  bones  strangely  like  the 
familiar  forms  of  to-day,  but  of  unknown  species  and 
unwonted  combinations.  The  Titanotherium  was  one  of 
these  wonderful  animals.  It  resembled  a  hornless  rhino- 
ceros, but  was  eighteen  or  twenty  feet  long,  and  nine  feet 
high. 

The  Origin  of  this  Region  was,  probably,  as  fol- 
lows :  The  great  Tertiary  sea  was  at  first  salt,  but  receiv- 


*  These  rocky  piles,  in  their  endless  succession,  assume  the  appearance  of 
maasive  artificial  structures  decked  out  with  all  the  accessories  of  buttress  arid 
turret,  arched  doorway  and  clustered  shaft,  pinnacle  and  finial  and  tapering 
spire.  On  a  nearer  approach  the  illusion  vanishes,  and  all  the  forms  which  fancy 
has  conjured  are  resolved  into  barren  desolation.  The  bottom  of  the  vale  is  an 
earth  of  chalky  whiteness,  baked  by  the  sun,  and  utterly  destitute  of  vegetation. 
The  water  which  oozes  out  of  the  foundation-wall  of  the  prairie  is  brackish  and 
unpalatable.  In  winter,  the  wind  and  snow  rush  through  the  lanes  and  corri- 
dors of  this  city  of  the  dead  in  eddying  whirls,  while  the  withered  grasses  and 
the  voiceless  and  motionless  solitude,  together  with  the  relentless  frost  and 
never-tiring  storm,  make  the  place  the  realization  of  utter  bleakness  and  desola- 
tion. In  summer  the  scorching  sun  literally  bakes  the  clays  which  have  been 
kneaded  by  the  frosts  and  thaws  of  spring ;  and  the  daring  explorer  of  the  scene 
finds  no  tree  nor  shrub  to  shelter  him  from  the  fervid  rays  poured  down  from 
above,  and  reflected  from  the  white  walls  which  tower  around  him,  and  the 
whHe  floor  which  almost  blisters  his  feet— Sketches  of  Creation —  Winchdl. 


206  THE    AGE    OP   MAMMALS. 

ing  fresh  water  from  the  drainage  of  the  adjacent  land, 
and  having  an  outlet  into  the  ocean,  it  gradually  became 
a  brackish,  and  at  last  a  fres.h-water  sea.  As  the  conti- 
nent was  elevated,  this  great  inland  sea  was  drained  in 
part,  and  in  time  probably  became  broken  up  into  a 

FIG.  ico. 


Testudo  Oweni. 

chain  of  fresh-water  lakes.*  The  basin  of  one  of  these, 
now  constituting  the  Bad  Lands,  is  thought  by  Hayden 
to  have  covered  an  area  of  150,000  square  miles — five 
times  as  great  as  that  of  Lake  Superior.  The  shores  of 
these  lakes  during  the  Tertiary  and  Post-Tertiary  Periods 
were  inhabited  by  the  rhinoceros,  elephant,  camel,  horse, 
beaver,  wild  cat,  wolf,  and  many  quadrupeds,  whose  en- 
tire species  are  now  extinct.  In  these  familiar  haunts, 


*  It  is  not  difficult,  with  the  discoveries  already  made  in  Colorado,  to  call  up 
the  country  as  it  existed  on  the  eastern  side  of  the  mountains  about  the  close  of 
the  Miocene  Period.  A  long  and  wide  lake  covered  the  spot  where  Golden  City 
and  Denver  now  stand,  and  stretched  north  and  south  for  an  immense  distance. 
Ita  banks  were  clad  with  forests  of  pines,  palms,  and  gum-bearing  trees.—  Denton. 


THE    POST-TERTIARY   PERIOD.  207 

amid  a  semi-tropical  vegetation,  they  lived  and  died. 
Their  remains,  sinking  in  the  soft  mud,  reveal  to  us 
to-day  the  forms  of  Tertiary  life. 

lf 

PO  ST-TERTI  A  RY      PE  R  I  0  D. 

(Quaternary  Epoch.) 

(  i.  Glacial  Epoch. 

POST-TERTIARY   P-ERIOD.  \  2.  Champlain  Epoch. 
(  3.  Terrace  Epoch. 

i.     G  LAC  I  AL     EPO  C  H. 

(Drift  or  Bowlder  Period) 

The  continent  has  been  steadily  growing  through  the 
ages  until  now  it  has  attained  its  full  dimensions.  It 
would  seem  to  be  ready  for  man.  It  abounds  in  coal, 
timber,  water,  game,  and  the  domestic  animals  necessary 
for  man's  use.  We  naturally  expect  his  creation  next, 
and,  almost  unconsciously,  look  about  for  traces  of  his 
presence.  But  God's  plan  is  not  yet  complete.  The  next 
perio.d  seems  one  of  retrogression,  and  a  superficial  view 
would  lead  one  almost  to  despair  of  the  result.  We  must 
not,  however,  be  impatient,  but  wait  the  slow  development 
of  Nature's  laws.  The  earth  having  passed  the  ordeal  by 
fire  and  water,  now  enters  upon  that  by  ice.  The  long 
summer  is  over.  For  ages  a  tropical  climate  has  pre- 
vailed, and  on  the  borders  of  the  Arctic  Ocean  animals 
have  roamed  and  plants  have  flourished  which  now  find 
a  home  only  beneath  the  burning  sun  of  the  Tropics. 
Their  reign  is  past.  A  tedious  Arctic  winter  succeeds. 
During  its  rigors  life  disappears,  and  half  of  the  conti- 
nent reverts  to  its  primeval  desolation.  Let  us  notice 


208  THE      AGE      OF.     MAMMALS. 

some  of  the  traces  of  this  wonderful  change  —  this  appar- 
ent check  in  the  world's  progress. 


.  —  This  includes  the  lopse  unstratified*  deposits 
of  clay,  sand,  gravel  and  stones  familiar  to  all  inhabit- 
ants of  the  northern  States.  It  does  not  extend  south  of 
latitude  39°  f  nor  west  of  the  Rocky  Mountains  (Whit- 
ney and  Foster).  In  some  places  the  Drift  material  forms 
only  a  slight  covering  over  the  solid  rock,  while  in  others 
it  is  piled  up  in  hills  and  ridges. 

BOWLDEES.  —  The  stones  are  of  all  sizes,  from  small 
cobble-stones  up  to  great  rock-masses.  In  Whittingham, 
Vt.,  is  a  bowlder  whose  length  is  forty  feet,  and  whose 
estimated  weight  is  3,400  tons;  another  in  Bradford 
weighs  over,  2,000  tons.  Plymouth  Eock  is  a  bowlder  of 
syenitic  granite,  ledges  of  which  are  to  be  seen  near 
Boston.  The  pedestal  of  the  statue  of  Peter  the  Great 
was  hewn  from  a  block  of  granite  weighing  1,500  tons, 
which  was  found  in  a  neighboring  marsh.  Bowlders  are 
sometimes  so  nicely  poised  that  they  can  be  rocked  by 
the  hand,  although  an  immense  force  would  be  required 
to  dislodge  them. 

Bowlders  are  more  or  less  rounded,  as  if  water-worn, 
and  their  structure  and  mineral  composition  are  different 
from  those  of  the  rocks  on  which  they  rest.  They  have 
evidently  been  transported  to  the  places  they  occupy. 


*  When  the  deposit  is  arranged  in  layers,  it  is  termed  Modified  Drift.  Mod- 
ified Drift  at  many  places  forms  knolls  of  a  most  picturesque  description.  On 
account  of  their  beauty,  they  are  oftentimes  chosen  for  burial  places.  Mt. 
Hope  at  Rochester,  and  Woodlawn  at  Elmira,  N.  Y.,  Mt.  Auburn  at  Cam- 
bridge,  and  the  cemeteries  at  Plymouth,  Newburyport,  and  ^forth  Adams,  Mass., 
are  all  delightfully  located  on  sites  of  this  formation. 

t  39°  is  about  the  latitude  of  Washington,  Cincinnati,  St.  'LiOais,  Kansas  City. 
Pike's  Peak,  and  Sacramento  City. 


THE    POST-TERTIARY    PERIOD. 


20$ 


The  "parent  ledges  "from  which  they  were  derived  can 
generally  be  found  at  the  north  of  the  locality— some- 


View  near  Gloucester,  Mass. 

times  at  a  distance  of  a  few  rods  only,  at  others  of 
many  miles.  Long  Island  and  Martha's  Vineyard  are 
covered  with  rocks  derived  from  the  main-land.  The 
southern  part  of  Rhode  Island  is  strewn  with  iron  ore 
from  Iron  Hill  (Cumberland,  K,  I.).  On  Hoosic  Moun- 
tain is  a  bowlder  of  500  tons  weight,  which  has  been 
carried  from  a  ledge  across  an  intervening  valley  1,300 
feet  deep,  and  at  the  same  time  elevated  1,000  feet  above 
its  source.  Masses  of  native  copper  from  Lake  Superior 
are  scattered  over  Wisconsin,  Michigan,  and  even  Ohio 
and  Indiana.  The  streets  of  Cincinnati  are  paved  with 
stones  quarried  by  the  hand  of  Nature  in  the  region  of 
the  Upper  Lakes  (Winchell).  Azoic  rocks  are  found 
on  the  western  prairies,  from  400  to  600  miles  distant 
from  their  homes.  Such  bowlders  are  significantly 


210  THE     AGE     OF    MAMMALS. 

termed  lost  rocks.*  A  bushel  of  pebble-stones  gathered 
in  any  northern  State  will  often  represent  nearly  every 
geological  formation  found  for  hundreds  of  miles  north 
of  that  locality. 

GLACIAL  S:rtiL#!. — A  careful  examination  of  many  of 
these  bowlders  shows  us  that -they  are  covered  with  paral- 
lel grooves  (strice).  These  have  obviously  been  caused 
by  the  scraping  of  the  bowlders  on  the  solid  rock,  as  if  the 
Drift  material  had  been  carried  forward  by  an  irresistible 
force,  since  the  "bed  rock"  (the  rock  in  place)  in  the 
regions  covered  by  the  Drift  is  polished  and  grooved  in  a 
similar  manner.  These  striae  consist  of  long,  straight, 
parallel  lines, — furrows  a  foot  broad  and  several  inches 
deep,  or  scratches  fine  as  a  pin  would  make.  The  sur- 
faces of  hard  rocks,  as  quartz,  -are  often  polished  smooth 
as  glass,  while  the  markings  can  be  seen  only  with  the 
microscope.  The  general  course  is  that  in  which  the 
bowlders  have  been  carried,  i.  e.,  from  north  to  south,  f 

*  In  New  England,  oftentimes  the  surface  for  many  miles  is  covered  with 
these  erratic  blocks  ;  on  the  prairies,  however,  they  are  found  only  occasionally. 
This  may  be  caused  by  the  different  character  of  the  rocks  at  the  east  and  at  the 
west.  While  every  location  shows  the  intrusion  of  foreign  material,  the  great 
mass  is  made  up  by  the  destruction  of  neighboring  rocks.  The  Silurian  and 
Devonian  rocks  of  the  Mississippi  valley  would  naturally  produce  a  soil  far 
different  from  that  of  the  crystalline  and  metamorphic  rocks  of  New  England. 
The  agent  which  transported  the  rocks  might  have  ground  the  softer  class  to  an 
impalpable  powder,  and  left  the  other  of  a  far  coarser  texture. 

t  "In  general,  these  striae  do  not  alter  their  course  for  any  topographical 
feature  of  the  country.  They  cross  valleys  at  every  conceivable  angle,  and  even 
if  the  striae  run  in  a  valley  for  some  distance,  when  the  valley  curves  the  striae 
will  leave  it,  and  ascend  hills  and  mountains  'even  thousands  of  feet  high.  But 
these  striae  are  never  found  upon  the  south  sides  of  mountains,  unless  for  a  part 
of  the  way  where  the  slope  is  small.  Mt.  Monadnoc,  of  New  Hampshire,  is  an 
illustration  of  these  statements.  It  is  a  naked  mass  of  mica  schist,  3,250  feet 
high,  rising  like  a  cone  out  of  an  undulating  country.  And  from  top  to  bottom 
it  has  been  scarified  on  its  northern  and  western  sides,  indicated  by  striae  run- 
ning up  the  mountain,  at  first  south-easterly,  and  at  the  top  at  S.  10*  E.  There 
are  deep  furrows  and  other  phenomena  on  the  summit,  and  the  striae  extend  a 
short  distepce  up  the  southern  slope  of  the  mountain."— Hitchcock. 


THE    POST-TERTIARY    PERIOD 


211 


varying  generally  not  more  than  20°  east  or  west.  There 
are  frequently  two  or  more  sets  of  striae,  differing  a  little 
in  direction.  At  Stony  Point,  Lake  Erie,  the  limestone 


FIG.  102. 


Bowlder  Scratches. 

lies  exposed  above  the  level  of  the  water.  The  bed  is 
planed  down  smooth  as  a  floor,  and  at  one  place  the  par- 
allel grooves  strikingly  resemble  the  deep  ruts  produced 
by  a  loaded  wagon.  On  the  Platte  river  there  is  a  ledge 
of  limestone  so  regularly  planed  that,  without  further 


212  THE    AGE     OF    MA  MM  A  L  S. 

working,  it  can  be  used  for  caps  and  sills  in  houses.  At 
Marquette,  on  Lake  Superior,  there  are  surfaces  as 
uniform  as  if  worked  to  a  level  and  afterward  rubbed 
with  sand-paper.  Near  the  sea-shore  at  Portland,  Maine, 
the  striae  run  parallel  for  great  distances  and  then  dis- 
appear in  the  water.  Everywhere  in  the  northern  part 
of  the  continent,  up  to  a  height  of  five  or  six  thousand 
feet  above  the  level  of  the  sea,  where  the  bed-rock  is 
laid  bare,  it  is  found  covered  with  these  Drift-tracings. 
We  can  best  understand  the  cause  of  the  Drift  phenom- 
ena by  noticing  similar  cases  now  exhibited  in  Alpine 
regions. 

GLACIAL  PHENOMENA.— The  snow  which  falls  on  the 
mountains  of  Switzerland,  above  the  height  of  9,000 
feet  does  not  melt,  but  accumulates  to  a  great  thickness. 
By  its  own  weight  it  generally  packs  into  a  solid  mass. 
Thawing  superficially  by  day,  tiny  streams  of  water  per- 
colate through,  and  convert  it  into  the  beautiful  azure- 
tinted  ice,  so  much .  admired  by  tourists.  Seas  of  ice 
(mers  de  glace)  fill  the  spaces  between  the  summits,  while 
from  them,  down  every  valley,  pour  rivers  of  ice,  glaciers, 
from  200  to  5,000  feet  deep.  These  ice-streams,  le^  by 
the  snows  above,  extend  downward  until  they  are  melted 
by  tha  summer  sun  in  the  valley  below.  They  sometimes 
plough  irresistibly  into  the  cultivated  fields,  so  that  a 
person  can,  with  one  hand,  touch  the  growing  corn,  and 
with  the  other  the  descending  ice-wall.  The  glacier  ad- 
vances down  the  mountain  at  the  rate  of  from  eight  to 
twelve  inches  per  day.  Frost,  rain,  hail,  and  avalanches 
of  snow  are  continually  detaching  from  the  mountain- 
peaks  masses  of  rock,  which  roll  down  upon  the  glacier. 
If  the  ice  were  stationary  these  would  merely  gather. in  a 


'i- 


•v 


THE     POST-TERTIARY    PERIOD.  215 

confused  pile,  but  owing  to  the  forward  movement  of  the 
glacier,  they  form  along  the  outer  edge  a  line  of  stones 
which  is  termed  a  Moraine.  When  the  rocks  fall  from 
opposite  mountains  and  on  each  side  of  the  glacier,  they 
make  two  parallel  trains  which  are  called  Lateral  Mo- 
raines (Fig.  103).  At  the  foot  of  the  glacier  the  debris 
gathers  in  ridges,  styled  Terminal  Moraines.*  In  this 
way  enormous  blocks  of  stone  have  been  carried  many 
miles.  They  are  often  found  perched  on  points  of  the 
Alps  far  above  existing  glaciers,  or  dispersed  over  distant 
plains.  Masses  thus  conveyed  on  the  surface  of  the 
glacier  are  little  worn.  Blocks,  pebbles,  etc.,  however, 
which  become  frozen  in  the  ice,  are  forced  along  in  the 
onward  progress  of  the  glacier,  scoring  the  rock  beneath 
with  parallel  lines,  and  smoothing  its  surface  as  emery 
polishes  steel,  while  they  are  themselves  rounded  and 
scratched  in  every  direction,  and  even*g1fa|j^d  into  im- 


palpable powder.     The  glacier  thus  .J^ewftes  a  gigantic 
ick,  OTfcu 


rasp  hundreds  of  feet  4hick,  OTfcusaniWfcsvid^  and  miles 
in  length,  scouring  the  rocks  between  and*bver  which 
it  passes. 

*  "The  masses  of  enow  which  hang  upon  the  Alps  during  winter,  the  rain 
which  infiltrates  between  their  beds  during  summer,  the  sudden  action  of  tor- 
rents of  water,  and  more  slowly,  but  yet  more  powerfully,  the  chemical  affini- 
ties, degrade,  disintegrate,  and  decompose  the  hardest  rocks.  The  debris  thus 
produced.  falls  from  the  summits  into  the  circles  occupied  by  the  glaciers  with  a 
great  crash,  accompanied  by  frightful  noises  and  great  clouds  of  dust.  Even  in 
the  middle  of  summer  I  have  seen  these  avalanches  of  stone  precipitated  from 
the  highest  ridges  of  the  Schreckhorn,  fonning  upon  the  immaculate  snow  a 
long  black  train,  consisting  of  enormous  blocks  and  an  immense  number  of 
smaller  fragments.  In  the  spring,  a  rapid  thawing  of  the  winter  snows  often 
eauses  accidental  torrents  of  extreme  violence.  If  the  melting  is  slow,  water 
insinuates  itself  into  the  smallest  fissures  of  the  rocks,  freezes  there,  and  rends 
asunder  the  most  refractory  masses.  The  blocks  detached  from  the  mountains 
are  sometimes  of  gigantic  dimensions  ;  we  have  found  them  sixty  feet  in 
length,  and  those  measuring  thirty  feet  each  way  are  by  no  means  rare  in  the 
Deux  Monties—  Martin. 


216  THE     AGE     OF    MAMMALS. 

Uridences  of  Former  Glaciers.  —  Moraines, 
erratic  blocks,  polished  surfaces,  striae,  etc.,  become  to 
the  geologist  infallible  signs  of  the  former  existence  of 
glaciers,*  and  enable  him  to  follow  them  in  their  course 
and  fix  their  origin.  One  who  is  familiar  with  tracing 
the  furrows  of  this  mighty  ice-plow  will  recognize  at  once 
where  the  large  bowlders  have  hollowed  out  their  deeper 
gashes,  where  small  pebbles  have  drawn  their  finer  marks, 
where  the  stones  with  angular  edges  have  left  their  sharp 
scratches,  and  where  fine  sand  and  gravel -have  rubbed 
and  smoothed  the  rocky  surface,  and  left  it  polished  as 
if  it  came  from  the  hand  -of  the  marble-worker. 

G2aciers  of  Greenland. — Glacial  phenomena  are 
displayed  on  the  grandest  scale  in  Greenland.  On  its 
western  coast  is  a  glacier  1,200  miles  long.  It  presents 
to  the  voyager  a  perpendicular  wall  of  ice  2,000  feet 
high.  A  great  glacial  river,  says  Kane,  seeking  outlets 
at  every  valley,  rolling  icy  cataracts  into  the  Atlantic  and 


*  Some  or  all  the  marks  above  enumerated  are  observed  in  the  Alps  at  great 
heights  above  the  present  glaciers  and  far  below  their  actual  extremities ;  also 
in  the  great  valley  of  Switzerland,  fifty  miles  broad ;  and  almost  everywhere  on 
the  Jura,  a  chain  whick  lies  to  the  north  of  this  valley.  The  average  height  of 
the  Jura  is  about  one-third  that  of  the  Alps,  and  it  is  now  entirely  destitute  of 
glaciers ;  yet  it  presents  almost  everywhere  similar  moraines,  and  the  same  pol- 
ished and  grooved  surfaces  and  water-worn  cavities.  The  erratics,  moreover, 
which  cover  it  present  a  phenomenon  which  has  estonlshed  and  perplexed  the 
geologist  for  more  than  half  a  century.  No  conclusion  can  be  more  incontest- 
able than  that  these  angular  blocks  of  granite,  gneiss,  and  other  crystalline  for- 
mations came  from  the  Alps,  and  that  they  have  been  brought  for  a  distance  of 
fifty  miles  and  upward  across  one  of  the  widest  and  deepest  valleys  in  the 
world ;  so  that  they  are  now  lodged  on  the  hills  and  valleys  of  a  chain  composed 
r<*  limestone  and  other  formation?,  altogether  distinct  from  those  of  the  Alps. 
Their  great  size  and  angularity,  after  a  journey  of  so  many  leagues,  have  justly 
excited  wonder;  for  hundreds  of  them  are  as  large  as  cottages;  and  one  in  par- 
ticular, composed  of  gneiss,  celebrated  under  the  name  of  Pierre  a  Bot,  rests  on 
the  side  of  a  hill  about  900  feet  above  the  Lake  of  Neufchatel,  and  is  no  less  than 
forty  feet  in  diameter.—  Lyell. 


THE     P  O  S  T-  TE  1!  TIA  R  Y     P  EH  I  OD.  .ill 

the  Greenland  seas,  and  at  last  reaching  the  northern 
limit  of  the  land  which  has  borne  it  up,  pours  a  mighty 
frozen  torrent  into  Arctic  space.  Unlike  the  Alpine 
glaciers,  which  melt  in  the  warm  valleys  below,  this 
empties  into 'the  ocean,  and  vast  masses  becoming  de- 
tached, are  floated  away,  to  be  dissolved  in  the  milder 
water  of  southern  seas.  Thousands  of  these  icebergs 
throng  the  northern  ocean,  freighted  with  debris  to  be 
deposited  on  the  sea-bottom  of  lower  latitudes.*  Could 
we  examine  the  track  of  these  ice-rafts,  we  should  doubt- 
less find  striae  cut  in  the  polished  rocks,  and  blocks  de- 
posited in  long  trains  where  the  bergs  had  struck, 
scraped  along  by  their  enormous  momentum  and  at 
last  stranded. 

We  are  now  prepared  to  understand  the  meaning  of 
the  Drift  phenomena. 

Origin- of  the  tDrift.  —  The  Arctic  regions  are 
elevated.f  The  climate  of  the  whole  continent  feels  the 
change.  The  cold  creeps  .down  every '  valley.  •  Each 
northern  blast  brings  a  frost.  The  verdure  of  forest 
and  plain  withers  and  falls.  The  sun  loses  a  part  of 
its  heat.  The  sea  becomes  cold.  Tertiary  life  perishes 


*  Describing  Cape  James  Kent,  Kane  says :  "As  I  looked  over  this  ice-belt, 
losing  itself  in  the  far  distance,  and  covered  with  millions  of  tons  of  rubbish- 
greenstones,  limestone;?,  chlorite  slates,  rounded  and  irregular,  massive  and 
ground  to  powder — its  importance  as  a  geological  agent  in  the  transportation  of 
Drift  struck  me  with  great  force.  Its  whole  substance  was  covered  with  these 
contributions  from  the  shore;  and  farther  to  the  south,  upon  the  now  frozen 
waters  of  Marshall  Bay,  I  could  recognize  raft  after  raft  from  last  year's  ice-belt, 
which  had  been  caught  up  by  the  winter,  each  one  laden  with  its  heavy  freight 
of  foreign  material.1' — Arctic  Expedition. 

t  It  is  proper  to  remark  that,  while  all  geologists  agree  as  to  the  temperature 
of  this  period,. all  do  not  accept  the  theoiy  given  above  as  to  the  cause  of  thy 
cold.  Many  different  opinions  are  advanced.  The  above  is  supported  by  Dana, 
Wine-hell,  and  many  prominent  geologists.  (See  note  in  (^UEPTIO^S.  p,  272.) 

10 


SIS  THE     AGE      OF     MAMMALS. 

in  this  frigid  temperature.  Arctic  vegetation  covers  the 
land  where  tropical  flowers  have  so  lately  bloomed  in 
beauty.  The  musk-ox  and  the  reindeer  roam  the  south 
of  Europe  where,  in  .modern  times,  are  to  grow  the  olive 
and  the  vine.*  New  species  of  animals  spring  into  being/ 
clothed  with  a  raiment  of  wool  to  protect  them  from 
the  rigors  of  the  climate,  and  furnished  with  teeth  of 
a  peculiar  complexity,  to  enable  them  to  browse  on 
the  new  vegetation.  The  seas  are  frozen  to  their  lowest 
depths.  Elvers  are  stopped  and  turned"  to  ice.  Snow 
gathers  in  the  wintry  air,  and  wraps  in  its  mantle  of 
white  all  the  desolation  that  has  been  wrought.  Glaciers, 
born  in  the  icy  north,  invade  the  land.  Sullenly  they 
move  southward,  along'  every  great  river  valley, f  plough- 
ing the  rock,  paring  down  acclivities,  filling  up  ancient 


*  In  the  Drift  are  found  the  musk-ox,  the  reindeer,  the  walrus,  the  seal,  and 
many  kinds  of  shells  characteristic  of  the  Arctic  regions.  The  northernmost 
part  of  Norway  and  Sweden  is  at  this  day  the  southern  limit  of  the  reindeer  in 
Europe ;  but  their  fossil  remains  are  found  in  large  quantities  in  the  Drift  about 
the  neighborhood  of  Paris,  and  quite  recently  they  have  been  traced  even  to  the 
foot  of  the  Pyrenees.  Side  by  side  with  the  remains  of  the  reindeer  are  found 
those  of  the  European  marmot,  whose  present  home  is  in  the  mountains,  about 
6,000  feet  above  the  level  of  the  seaj  The  occurrence  of- these  animals  in  the  super- 
ficial deposits  of  the  plains  of  Central  Europe,  one  of  which  is  now  confined  to 
the  high  north,  and  the  other  to  mountain-heights,  certainly  indicates  an  entire 
change  of  climatic  conditions,  since  the  time  of  their  existence.  European  shells 
now  confined  to  the  Northern  Ocean,  are  found  as  fossils  in  Italy— showing-that, 
while  the  present  Arctic  climate  prevailed  in  the  Temperate  Zone,  that  of  the 
Temperate  Zone  extended  much  farther  south  to  the  regions  we  now  call  sub- 
tropical. In  America  there  is  abundant  evidence  of  the  same  kind ;  throughout 
the  recent  marine  deposits  of  the  Temperate  Zone,  covering  the  low  lands  above 
tide-water  on  this  continent,  are  found  fossil  shells,  whose  present  home  is  on 
the  shores  of  Greenland.  It  is  not  only  in  the  Northern  hemisphere  that  these 
remains  occur,  but  in  Africa  and  in  South  America,  wherever  there  has  been  an 
opportunity  for  investigation,  the  Drift  is  found  to  contain  the  traces  of  animals 
whose  presence  indicates  a  climate  many  degrees  colder  than  that  now  prevail- 
ing there.—  Agassiz's  Geological  Sketches. 

t  The  Connecticut  Valley  seems  to  have  had  an  Independent  glacier,  as  the 
striae  are  parallel  with  the  general  course  of  the  river ;  the  Mohawk  another ;  the 
Hudson  a  third  one  ;  and  traces  of  many  smaller  ones  are  being  discovered. 


THE     POST-TERTIARY    PERIOD.  21V 

river-channels,*  burying  forests  under  masses  of  debris, 
scoring  and  polishing  the  surface,  grinding  up  the  stones 
into  soil,  and  strewing  rocks,  gravel,  and  sand  over  south- 
ern fields.  Reaching  the  coast  of  New  England,  they  fringe 
the  ocean  with  an  ice-  wall  for  hundreds  of  miles.  Mighty 
icebergs,  breaking  loose,  float  southward,  and,  grinding 
their  way  through  river-channel  and  strait,  deposit  their 
rocky  burdens  in  long  trains  over  the  sea-bottom,  f  or, 
grounding  on  its  shore,  drop  them  in  promiscuous  piles. 

II.  CHAMPLAIN  AND  TERRACE  EPOCHS. 


^Depression    .of    Ike     Continent 

ET>OCH).—  The  epoch  of  Arctic  elevation  ceases.  The 
northern  regions  descend  toward  their  former  level. 
Again  the  continent  feels  a  change.  A  geologic  spring- 


*  There  is  proof  of  the  existence  of  rivers  in  different  channels  from  the 
present.  At  the  Whirlpool,  on  the  west  bank  of  the  gorge,  three  miles  below 
Niagara  Falls,  there  Is  a  deep  ravine  filled  with  gravel  and  sand.  This  old  chan- 
nel can  be  traced  to  Lake  Ontario,  four  miles  west  of  the  present  mouth  of  the 
river,  and  must  have  been  the  ancient  bed.  During  the  Glacial  Epoch,  the 
mighty  ice-plow  pared  off  the  ridge,  and  filled  the  ravine  with  Drift  materials, 
so  that  the  river  was  forced  to  seek  a  new  route,  and  since  then  has  worn  away 
the  present  tremendous  gorge  between  Queenstown  and  the  Falls.  In  boring 
for  oil,  and  in  excavating  for  railroads,  such  ancient  river-channels,  now  filled 
•with  Drift,  are  frequently  found. 

"  In  excavating  one  of  the  canals  for  supplying  the  mills  of  Lowell,  the  old 
channel  of  the  Merrimack  was  found  under  the  Drift  and  alluvium,  half  a  mile 
from  the  present  bed  of  the  river."— L.  S.  Burbank.  • 

t  "There  is  one  of  these  trains  in  Berkshire  county,  Mass.  The  moun- 
tains from  which  the  angular  blocks  of  hard  talcose  slate  have  been  torn 
off,  lies  in  Canaan,  N.  Y. ;  and  from  thence  they  lie  in  trains,  running  for  a 
few  miles.  S.  56°  E.,  and  then  changing  to  S.  34°  E.,  and  extending  yet  further, 
making  in  the  whole  distance  not  less  than  fifteen  or  twenty  miles  ;  at  least  one 
of  them  extends  that  distance,  passing  obliquely  over  mountain  ridges  some 
600  or  800  feet  high.  Its  width  is  not  more  than  thirty  or  forty  rods-.  The  blocks 
are  of  all  sizes,  from  two  or  three  feet  in  diameter  to  those  containing  1(5,000 
cubic  feet,  and  weighing  nearly  1,400  tons,  and  in  some  places  almost  cover  the 
Burfrce  of  the  common  Drift,  and  are  not  mixed  with  \t"-Hitchcock. 


220 


THE     AGE     OF     MAMMALS. 


time  has  come.    The  fetters  of  winter  fall  off.    The  glacier 
feels  the  touch  of  heat,  and  myriad  streams  leap  gladly 

FIG  .104 


Stream  issuing  from  a  Glacier. 

forth.  The  snow-fields  disappear.  Torrents  of  water, 
hastening  to  the  ocean,  deluge  the  continent.  They  cover 
the  southern  States  with  fine  sediment,  the  debris  of  the 


THE     POUT- TERTIARY    PERIOD.  221 

glacier,  and  strew  pebbles  from  the  Appalachian  to  the 
very  border  of  the  Gulf*  (Winchell).  A  genial  warmth 
pervades  the  air.  Vegetation  springs  to  life.  The  de- 
pression of  the  land  still  continues.  The  ocean  covers 
a  part  of  Maine.  The  River  St.  Lawrence  and  Lake 
Champlain  become  arms  of  the  sea,  tenanted  by  seals 
and  whales.  The  valleys  are  filled  with  broad,  deep, 
majestic  rivers,  whose  waters,  flowing  to  the  sea,  dig 
deep  channels,  open  new  routes  to  the  ocean,  plough 
through  mountain-ridges,  sort  and  sift  the  Drift  debris, 
arranging  it  in  layers,  and  forming  alluvial  deposits  of  a 
great  thickness.  In  many  parts  of  the  northern  States, 
only  the  loftiest  mountains  emerge  above  the  engulf- 
ing waters.  Billows  roll  wTh  ere  birds  sang  and  flowers 
bloomed.  The  land  gained  during  all  these  long  ages  of 
geological  history  seems  lost  again.  The  ocean  triumphs, 
and  once  more  the  Gulf  joins  its  waters  with  the  Arctic 
Ocean. 

l?leratio?i  of  the  Continent  (TERRACE  EPOCH). 
—Slowly  the  continent  rises  from  its  last  baptism.  Be- 
fore reaching  its  former  level  it  stops.  The  rivers  dig 
deeper  channels  in  the  soft  alluvial  deposit  of  the  valleys, 
and  leave  their  former  banks  far  up  on  side-hills  to  mark 
their  submersion  during  the  Cha-mplain  .Epoch.  The 
lakes  retire  to  smaller  limits  and  form  new  beaches  like 
the  old  they  have  deserted.  The  ocean  yields  the  sea- 
coast,  where  it  has  so  recently  dashed  in  eager  conquest, 
and  the  land  it  has  just  reclaimed,  and  sullenly  retreats. 


*  There  are  no  "  cobble-stones11  in  the  southern  States.  The  streams-do  not 
seem  to  have  had  sufficient  force  to  carry  the  coarse  material  of  the  Drift.  Thus 
the  sediment  naturally  becomes  finer  toward  the  eouth,  and  coarser  north. 


;• 


THE     AGE     OF    MAMMALS. 

* 

There  are  several  pauses  of  this  kind  in  the  upward 
progress  of  the  continent.*  At  each  stage  the  retiring 
waters  toy  with  the  sand  and  gravel,  arrange  them  in 
beds,  spread  the  alluvial  soil  upon  the  muddy  bottom, 
and  put  the  finishing  strokes  to  the  work  of  fitting  the 
continent  for  man's  use. 

Y  -  ^Proofs  of  these  Oscillations. — Over  the  entire 
continent  we  find  in  the  river  valleys,  overlying  the  true 
Drift,  alluvial  deposits  *  reaching  far  above  the  present 

FIG.  105. 


Terraces  on  Connecticut  River,  south  of  Hanover,  N.  H.  (Dana). 


*  The  theory  given  in  the  text  is  that  generally  received.  The  author,  how- 
ever, does  not  himself  believe  in  these  extreme  oscillations  of  the  continent, 
and  its  submergence  to  the  extent  claimed,  by  many  geologists.  Some  places 
have  doubtless  been  too  hastily  accepted  as  sea-beaches,  and  the  whole  subject 
demands  more  careful  investigation.  There  is  reason  to  believe,  however,  that 
at  this  period  the  Great  Lakes  were  filled  with  salt  water  and  inhabited  by  Arctic 
fauna.  Their  depths  are  even  now,  probably,  tenanted  by  life  of  that  type. 


THE     POST-TERTIARY    PERIOD. 

river  beds.  Looking  up  or  down  the  banks  of  almost  any 
principal  river,  one  can  trace  horizontal  lines,  marking 
one  or  more  terraces  indicating  the  higher  level  of  the 
stream  in  'former  times.*  Many  villages  owe  the  beauty 
of  their  sites  to  these  natural  terraces.  At  a  distance 
from  the  present  shore  of  lakes,  we  find  beaches  of  sand 
and  gravel  similar  to  those  now  existing  on  the  borders 
of  the  lakes,  and,  in  general,  parallel  with  them.  There 
are  several  of  these  on  the  south  shore  of  Lake  Erie ;  one 
extending  for  many  miles  is  locally  known  as  the  "  Ridge 
Road."  At  Mackinac  there  are  three  of  these  stair-like 
ridges,  the  highest  100  feet  above  the  present  water-level,  f 
Remains  of  whales  and  seals  have  been  found  at  Mon- 
treal, and  the  skeleton  of  a  whale  has  been  dug  up  on  the 
borders  of  Lake  Champlain,  sixty  feet  above  its  present 
level.  Near  Brooklyn  a  sea-beach  exists  100  feet  above 
the  ocean.  Along  the  River  St.  Lawrence,  and  in  the 
Champlain  and  Hudson  valleys,  there  are  deposits  termed 
"  Champlain  Clays,"  containing  marine  shells.  They  are 
found  over  500  feet  above  the  ocean!  It  is  evident  that 


*  I  counted  to-day  forty-one  distinct  ledges  or  shelves  of  terrace  embraced 
between  our  water-line  and  the  syenitic  ridges  through  which  Mary  River  forces 
itself.  These  shelves,  though  sometimes  merged  into  each  other,  presented  dis- 
tinct and  recognizable  embankments  "or  escarps  of  elevation.  Their  surfaces 
were  at  a  nearly  uniform  inclination  of  descent  of  5%  and  their  breadth  either 
12,  24,  36,  or  some  other  multiple  of  twelve  paces.  This  imposing  series  of 
ledges  carried  you  in  forty-one  gigantic  steps  to  an  elevation  of  480  feet ;  and  as 
the  first  rudiments  of  these  ancient  beaches  left  the  granite  which  had  once 
formed  the  barrier  sea-coast,  you  could  trace  the  passing  from  Drift-strewn  rocky 
barricades  to  clearly-defined  and  gracefully  curved  shelves  of  shingle  and 
pebbles.  I  have  studies  of  these  terraced  beaches  at  various  points  on  the 
northern  coast  of  Greenland.  They  are  more  imposing  and  on  a  larger  scale 
than  those  of  Wellington  Channel,  which  are  now  regarded  by  geologists  as  in- 
dicative of  secular  uplift  of  coast.— Kane's  Arctic  Explorations. 

t  When  the  lake  stood  at  this  level,  it  is  probable  that  the  water  poured  in 
floods  down  the  Illinois  River  valley,  swelling  it  to  a  mighty  stream.  Traces  of 
its  former  grandeur  are  abundant  far  above  its  present  banks. 


£J4  THE     AGE     OF    MAMMALS. 

the  banks  exhibiting  these  remains  were  ancient  sea- 
beaches,  and.  that  the  ocean  level  has  since  sunk  and  the 
laud  risen.* 

Fossils  of  the  (Post  -  2'erliary  ^Period.  —  This 
.is  the  current  era  of  geologic  history.  The  record  no 
longer  lies  deep  in  the  solid  rock.  We  find  it  in  the 


*  The  most  distinct  beaches  occnr  below  1,200  feet  above  the  ocean  level.  A 
very  fine  beach,  however,  is  found  on  the  west  side  of  the  Green  Mountains,  in 
West  Hancock,  Vt.,  2,196  feet  high.  Others  are  found  in  Peru,  Mass.,  2,022 
feet ;  at  the  Franconia  Notch  of  the  White  Mountains,  2,665  feet ;  and  at  the 
Notch  of  the  White  Mountains  (Gibb's  Hotel),  2,020  feet,  Upon  comparing  to- 
gether the  heights  of  beaches  in  different  parts  of  New  England,  we  find  a  num- 
ber of  them  having  essentially  the  same  elevatkm  ;  thus  showing  that  they  were 
formed  contemporaneously.  For  example,  there  are  beaches  in  Ashfield  and 
Shutesbury,  Mass. ;  in  Norwich,  Corinth,  Elmore,  Hardwick,  and  Brownington, 
Vt.,  each  1,200  feet  above  the  ocean,  and  the  most  remote  are  nearly  200  miles 
apart.— Hitchcock"1  s  Elementary  Geology, 

•  Page,  in  •'  Chips  and  Chapters,"  referring  to  the  raised  beaches  and  submarine 
forests  of  Great  Britain,  remarks  substantially  as  follows  :  From  120  feet  down 
to  the  present  sea-level  we  have  a  series  of  well-marked  shore-lines— 120,  63,  40, 
25,  and  12  feet— marking  a  succession  of  uprises,  all  clearly  pre-historic,  if  wo 
except  the  last,  which  indicates  no  very  high  antiquity.  Every  successive  uplift, 
while  it  increased  the  dimensions  of  the  British  Islands,  also  decreased  the 
general  temperature  of  the  country  in  the  proportion  of  1°  F.  for  every  250  feet 
of  uprise  or  nearly.  These  raised  beaches  arc  not  all  alike  well  marked  and 
decided,  owing  partly  to  the  nature  of  the  rocks  into  which  they  have  been  re- 
spectively cut,  and  partly  to  the  length  of  time  at  which  the  sea  stood  at  these 
respective  levels.  The  lowest  or  twelve-feet  beach  is  generally  marked  by  ter- 
races of  recent  shells  and  gravel.  Though  the  latest  of  British-raised  beaches, 
this  uprise  must  have  taken  place  long  antecedent  to  history;  and  there  is  not; 
so  far  as  we  are  aware,  any  certain  evidence  either  of  upheaval  or  depression 
since  the  time  of  the  Eomans,  although  certain  misinterpreted  appearances  have 
led  some  observers  to  an  opposite  conclusion.  Any  remains  found  in  the  caves 
of  the  twelve-feet  beach  are  savage  and  pre-Celtic,  showing  that  the  uprise  had 
taken  place  before  (perhaps  long  before)  the  occupation  of  these  primitive  inhab- 
itants. The  twenty-five-feet  beach  is  perhaps  the  most  striking — stretching  for 
miles  in  unbroken  continuity,  composed  in  many  districts  of  recent  shells  and 
gravel,  frequently  backed  by  old  caverned  cliffs,  and  forming  the  level  site  for 
most  of  our  modern  sea-ports  and  fashionable  watering-places.  The  sixty-three- 
feet  beach  is  also  well  defined  on  many  tracts  of  the  seaboard,  but  its  once  over- 
hanging cliffs  have  been  obliterated  by  the  tear  and  wear  of  the  elements,  its 
shells  and  exuvise  dissolved  and  destroyed,  and  its  gravel  beds  now  covered  by 
soil  and  greensward.  Of  the  higher  beaches  little  is  known  with  precision  or 
accuracy. 


THE     POST-TERTIARY    PERIOD.  225 

marls  and  sediment  of  filled  -  tip  lakes ;  in  beds  of 
sand  and  -clay  ;  in  the  alluvial  deposits  of  rivers ;  in  the 
growth  of  peat-bogs  and  mornss'es ;  in  the  deep,  muddy 
accumulations  of  swamps ;  in  the  stalagmites  of  fissures 
and  caverns,  and  in  the  ice  of  Arctic  regions.  The 
plant-remains — willow,  hazel,  fir,  beech,  and  oak — are 
familiar  to  those  who  now  live  in  the  same  latitudes. 
The  fres*h-water  shells  are  identical  with  those  which 
throng  the  neighboring  ponds.  The  marine  fossils — 
oysters,  clams,  mussels,  etc. — cannot  be  distinguished 
from  those  which  inhabit  the  surrounding  ocean.  When, 
however,  we  turn  to  the  land  animals,  the  change,  prob- 
jibly  through  the  instrumentality  of  man,  becomes  more 
apparent.  Tho  quadrupeds,  as  in  the  Tertiary  Period, 
tako  tho  precedence,  and  attract  our  attention  by  their 
enormous  liill:.  Wo  shall  describe  the  following:  the 
mammoth,  mcistodo:i9  megatherium^  glyptodon,  Irish  elk, 
cave-bear,  and  hyena. 

1.  THE  MAMMOTH,  or  fossil  elephant,  was  about  one- 
third  larger  than  any  known  to  modern  times.  A  tooth,  in 
the  Ward  cabinet,  Rochester,  weighs  fourteen  pounds.  This 
animal  wandered  in  great  herds  over  England,  thence  to 
Siberia,  and  across .  Behring's  Straits  into  North  America. 
Its  remains  are  very  abundant.*  Over  2,000  molar-teeth 


*  In  1GG3,  Otto  von  Guericke,  the  illustrious  inventor  of  the  air-pump,  wit- 
nessed the  discovery  of  the  bones  of  an  elephant  buried  in  the  shelly  limestone, 
or  muschelkalk.  Along  with  it  were  found  its  enormous  tusks,  which  should 
have  sufficed  to  establish  its  zo51ogical  origin.  Nevertheless  they  were  taken 
for  horns,  and  the  illustrious  Leibnitz  composed,  out  of  the  remains,  a  strange 
animal,  carrying  a  horn  in  the  middle  of  its  forehead,  and  in  each  jaw  a  dozen 
molar-teeth  a  foot  long.  Having  fabricated  this  fantastic  animal,  Leibnitz 
named  it  also ;  he  called  it  the  fossil  unicwn.  For  over  thirty  years  the  uni- 
roni  of  Leibnitz  was  universally  accepted  throughout  Germany,  and  nothing 
lc~>>  than  tho  discovery  of  the  entire  skeleton  of  the  mammoth  could  change  the 


226 


THE     AGE      OF     MAMMALS. 


were  found  in  a  few  years  by  the  fishermen  of  the  little 
village  of  Happisburg.     The  islands  in  the  sea  north  of 


FIG.  106. 


The  Mammoth  or  Fossil  Elephant. 


THE     POST-TERTIARY    PERIOD.  227 

Siberia  are-  but  conglomerations  of  sand,  ice,  and  the 
tusks  and  teeth  of  elephants.  During  every  storm,  the 
waves  wash  loose  and  cast  ashore  this  fossil  ivory,, which 
becomes  a  profitable  article  of  commerce.  Single  tusks 
are  found  weighing  over  200  pounds.  In  1844,  16,000 
pounds  are  said  to  "have  been  sold  at  St.  Petersburg. 
The  ivory  thus  obtained  has  been  exported  to  China  for 
five  centuries,  and  yet  the  supply  seems  undiminished. 
The  colossal  size  of  these  remains  has  given  rise,  among 
the  Tartars,  to  a  curious  legend.  They  were  believed  to 
belong  to  an  enormous  animal — an  elephantine  mouse — 
which  lived  underground,  like  the  mole,  and  which  in- 
stantly perished  when  exposed  to  the  least  ray  of  sun  or. 
moon-. 

In  1799,  a  fisherman  discovered  among  the  icebergs  on 
the  banks  of  the  Lena,  an  odd-shaped  block  of  ice.  Two 
years  after,  he  found  the  tusks  and  flank  of  a  mammoth 
protruding  from  it,  and  in  five  years  the  entire  body  be- 
came disentangled,  and  fell  upon  the  sand.  He  removed 
the  tusks  -and  sold  them.  Two  years  subsequent,  Mr. 
Adams,  of  the  St.  Petersburg  Academy,  heard  of  the  dis- 
covery, and  visited  the  spot.  The  people  of  the  neigh- 
borhood had  cut  off  pieces  of  the  flesh  for  their  dogs,  and 
wild  beasts  had  mangled  it,  but  the  skeleton  was  nearly 
entire.  The  skin  yet  covered  the  head ;  one  of  the  ears, 
well  preserved,  was  furnished  with  a  tuft  of  hair;  the 
neck  had  a  flowing  mane ;  and  the  body  retained  scat- 


popular  opinion,  and  then  iiot  without  a  keen  controversy.  In  1700,  a  veritable 
cemetery  of  elephants  was  discovered  near  the  banks  of  the  Necker  River,  in 
Wurtemberg.  Not  less  than  sixty  tusks  were  exhumed.  As  a  cnrious  instance 
of  the  superstition  of  the  times,  the  fact  may  be  mentioned  that  the  court 
physician  possessed  himself  of  the  fragments  which  were  left,  to  aid  him  in  com- 
bating fever  and  colic !  Chinese  apothecaries  now  use  similar  remedies. 


228 


THE     AGE     OF    MANUALS. 


tered  tufts  of  reddish  wool  and  black  hair.  Mr.  Adams 
collected  the  bones,  repurchased  the  tusks — which  were 
more  than  nine  feet  long— and  sold  this  unique  specimen 
to  the  Emperor  of  Eussia  for  $6,000. 

2.  THE  MASTODON  resembled  the  modern  elephant,  but 
had,  in  general,  a  longer  body  and  more  massive  limbs. 


The  Mastodon. 


"When  discovered,  Buffon  called  this  animal  the  Elephant 
of  the  Ohio.  A  single  tooth,  however,  is  sufficient  to  dis- 
tinguish its  remains.  The  grinding  surface  of  a  masto- 
don's tooth  is  covered  with  conical  projections — whence 
the  name  of  the  animal — while  that  of  the  elephant  is 
flat.  Teeth  have  been  dug  up  weighing  seventeen  pounds 
each,  and  tusks  fourteen  feet  in  length.  Six  skeletons 


THE     POST-TERTIARY    PERIOD.  229 

were  found  in  Warren  county,  N.  J.,  by  a  farmer  digging 
in  a  bog.  Within  the  ribs  of  one  of  them,  being  evidently 
the  contents  of  the  stomach,  were  seven  bushels  of  vege- 
table matter,  which,  on  microscopic  examination,  proved 
to  consist  of  cedar  twigs,  which  probably  formed  tho 
animal's  last  supper.  Similar  discoveries,  and  also  the 
form  of  the  teeth,  prove  that  its  food  was  roots,  small 
branches,  leaves,  grass,-  etc.  The  mastodon  was  once 
common  in  the  United  States,  and  probably  wandered 
in  herds  over  all  the  country  west  of  the  Connecticut 
Kiver. 

3.  THE  MEGATHERIUM  *  (monstrous  beast),  at  first 
sight  seems  the  most  ill-formed  creature  we  have  yc'; 
considered.  We  shall,  however,  find  its  structure  full  of 
harmony  and  adaptation.  It  was  simply  a  huge  sloth  of 
the  size  of  an  elephant.  Like  the  sloth  it  fed  on  leaves, 
and  possibly  like  the  ant-eater,  it  burrowed  deep,  in  the 
earth.  Its  fore-feet  were  each  three  feet  long  and  a  foot 
broad,  and  were  furnished  with  gigantic  claws.  Its  tail 
was  two  feet  in  diameter,  and  must  have  assisted  in 
supporting  its  huge  body,  as  it  tore  down  trees  for  its 
food,  while  it  constituted  also  a  powerful  means  of  de- 
fence. Its  massive  proportions  and  clumsy  form  rendered 
it  extremely  slow  in  its  movements,  but  there  was  no 
need  of  rapid  locomotion  in  an  animal  thao  merely  bur- 
rowed for  roots  or  browsed  for  leaves  in  a  tropical  forest ; 
neither  was  there  necessity  for  flight,  when  its  most  dan- 
gerous foe,  the  crocodile*  could  be  destroyed  by  a  single 
blow  from  its  gigantic  tail.  Thus  this  mighty  creature 


*  The  megatherium  is  shown  in  Fi.cr.  Ill,  on  the  right  hand ;  the  glyptodon  in 
frcnt  fit  tho  renter,  tho  mylodon  just  back  holding  on  to  rv  tree,  and  the  masto- 
don a:  the  left  nnd  in  the  rear. 


230  THE     AGE      OF     MAMMALS. 

lived  peaceful  and  respected  in  spite  of  its  apparently 
unwieldy  structure.* 

-  4.  THE.  GLYPTODOK  (sculptured  tooth)  was  a  mammal 
clad  iir  the  shell  of  a  turtle.  This  defensive  armor  mea- 
sured sometimes  eleven  feet  in  length,  and  weighed  1,000 
pounds. 

FIG.  108. 


Glyptodon  clavipes. 


5.  THE  IRISH  ELK  was  a  magnificent  and  imposing 
animal.     Its  antlers  were  often  ten  feet  long,  and  spread, 
from  one  tip  to  the  other,  a  distance  of  three  or  four 
yards. 

6.  THE  CAVE  BEAR  was  the  most  formidable  of  the 
ancient  flesh-eating  animals. 

It  'attained  the  size  of  a  large  horse.     Some  of  the 


*  During  the  dry  season  a  hunter  discovered,  on  the  banks  of  the  River 
Salado,  S.  A.,  what  appeared  to  be  the  trunk  of  a  tree.  Throwing  his  lasso  over 
it,  with  the  help  of  a  comrade  he  drew  it  upon  the  bank.  It  proved  to  be  an 
enormous  bone  five '  feet  through ;  the  pelvis  of  what  has  since  been  happily 
styled  the  megatherium.  To  this  countryman  the  bone  appeared  useless.  It 
did  not  make  half  as  good  a  seat  as  a  bullock's  skull— the  arm-chair  of 
the  pampas.  Finally  this,  with  other  bones,  was  sent  as  a- curiosity  to  the 
owner  of  the  land  on  which  they  were  discovered.  Sir  W.  Parish  found  them 
here,  dug  out  others,  and  forwarded  them  to  England.  From  these  remains  the 
casts  now  in  Boston,  Amherst,  etc.,  were  made. — Denton  in  "  Our  Planet." 


THE     POST-TERTIARY     PERIOD. 


231 


skeletons  are  ten  feet  long  and  six  feet  high.  The  ani- 
mal is  so  named  because  it  dragged  its  prey  into  caves, 
where  the  remains  of  a  large  number  of  antediluvian 
repasts  are  found  buried  in  the  stalactites  which  have 

/ 
„     d^t/Ws*^ 

/  r 

fcuJslA 


The  Irish  Elk. 


since  accumulated  on  the  floor.  In  the  celebrated  cave 
at  Gaylenreuth,  portions  of  the  skeletons  of  800  cave- 
bears  have  been  identified. 


TUB     AGE     OF    31 A 


'AL  S. 


7.  Tns  HYENA  was  very  abundant  in  England.  The 
bones  of  seventy-five  have  been  discovered  in  a  single 
cavern.  The  cave  at  Kirkdale,  England,*  is  noted  as  an 


FIG.  no. 


Cave  Bear  and  Hveua. 


*  In  the  summer  of  1821,  some,  workmen  em-ployed  in  quarrying  stone  upon 
fche  slope  of  a  limestone  hill  at  Kirkdale,  in  Yorkshire,  came  accidentally  upon 
the  mouth  of  a  cavern.  Overgrown  with  grass  and  bushes,  the  mouth  of 
this  cave  -in  the  hill-side  had  been  eflecttially  closed  against  all  intruders,  and 


' 


- 


v  ?  ix^ 

sU 


c 


! 


THE     POST-TERTIARY    PERIOD.  236 

ancient  haunt  of  these  animals.  "The  stalagmitic  de- 
•  posit  in  this  cavern,  with  its  projecting  bones/'  says 
Buckland,  "looks  like  a  pigeon-pie  with  pigeon's  legs 
sticking  through  the  crust."  , 

In  Fig.  110,  a  cave-bear  is  seen  sitting  at  the  mouth  of 
its  den,  watching  the  bones  of  an  elephant,  while,  above, 
a  hyena  waits  the  proper  moment  to  dispute  possession 
with  its  formidable  rival. 


its  existence  had  never  been  suspected.  The  hole  was  just  large  enough  to  admit 
a  man  on  his  hands  and  knees,  and  led  into  a  low  broad  cavern,  with  branches 
opening  out  from  it— some  of  which  have  not  yet  been  explored.  The  whole 
floor  was  strewn  with  hundreds  of  bones,  like  a  huge  dog-kennel.  The  workmen 
wondered  a  little  at  their  discovery,  but,  remembering  that  there  had  been  a 
murrain  among  the  cattle  in  that  region  some  years  before,  concluded  that  these 
must  be  the  banes  of  cattle  which  then  died  in  great  numbers  ;  and  having  thus 
satisfactorily  settled  the  matter,  threw  out  the  bones  on  the  road  with  the  lime- 
stone. A  gentleman,  living  near,  preserved  them ;  and  in  a  few  months,  Dr. 
Buckland,  the  great  English  geologist,  visited  Kirkdale,  and  examined  its  strange 
contents,  which  proved  indeed  stranger  than  any  one  had  imagined ;  for  many  of 
these  remains  belonged  to  animals  never  before  found  in  England.  The  bones  of 
hyenas,  tigers,  elephants,  rhinoceroses,  and  hippopotamuses  were  mingled  with 
those  of  deer,  bears,  wolves,  foxes,  and  many  smaller  creatures.  The  bones 
were  gnawed,  and  many  were  broken,  evidently  not  by  natural  decay,  but  as  if 
snapped  violently  apart.  After  a  complete  investigation,  Dr.  B.  convinced  him- 
self, and  proved  to  the  satisfaction  of  all  scientific  men,  that  the  cave  had  been  a 
den  of  hyenas  at  a  time  when  these  animals,  as  well  as  tigers,  elephants, 
etc.,  existed  in  England  in  as  great  numbers  as  they  now  do  in  the  wildest  parts 
of  tropical  Asia  or  Africa.  The  narrow  entrance  to  the  cave  still  retains  the 
marks  of  grease  and  hair,  such  as  are  seen  on  the  bars  of  a  cage  in  a  menagerie, 
against  which  the  imprisoned  animals  constantly  rub  themselves,  and  there 
were  similar  marks  on  the  floor  and  walls.  The  hyenas  were  evidently  the 
lords  of  this  ancient  cavern,  and  the  other  animals  their  unwilling  guests ;  for 
the  remains  of  the  latter  had  been  most  gnawed,  broken,  and  mangled ;  and  the 
head  of  an  enormous  hyena,  with  gigantic  fangs  complete,  testified  to  their  great 
size  and  power.  Some  of  the  animals,  such  as  the  elephants,  rhinoceroses,  etc., 
could  not  have  been  brought  into  the  cave  without  being  first  killed  and  torn 
to  pieces.  But  their  gnawed  and  broken  bones  attest  that  they  were  de- 
voured like  the  rest ;  and  probably  the  hyenas  then  had  the  same  propensity 
which  characterizes  those  of  our  own  time — to  tear  in  pieces  the  body  of  any 
dead  animal,  and  carry  it  to  their  den  to  feed  upon  it  apart.  (Agassiz.)— A  de- 
tailed account  of  this  investigation,- etc.,  may  be  found  in  "Reliquiae  Diluvi- 
anse,"  by  Dr.  Buckland. 


286 


THE 


OF    MAMMALS. 


.-—  /.  Glacial  IZpoch  on  the  ^Pacific 
Coast.  — California  shows  no  traces  of  northern  Drift.* 
The  Eocky  Mountains  probably  constituted  a  sufficient 
barrier  against  the  advancing  glacier  that  overwhelmed 
so  large  a  portion  of  the  continent.  Yet  no  section  ex- 
hibits more  frequent  signs  of  glacial  action.  The  glaciers 
were,  however,  confined  to  the  elevated  regions  of  the 
mountains,  as  the  conspicuous  moraines,  striae,  etc.,  abun- 
dantly prove.  Swift  torrents  sweeping  down  the  slopes 
of  the  mountain  ranges  denuded  extensive  regions  and 


Cafion  of  Grand  River. 

deposited  vast  quantities  of  Drift-material.     This  erosive 
action  doubtless  broke  up  the  auriferous  rocks  and  as- 

*  Whitney  in  Proc.  Cal.  Acad.  Nat.  Sci.    Foster  says  the  same  remark  holds 
true  throughout  Oregon. 


THE     POST-TERTIARY    PERIOD.  231 

sorted  the  materials  of  the  rich  gold-fields  of  California. 
The  great  canons  (can-yones)  of  the  Colorado  and  other 
western  rivers  are  believed  by  Newberry  to  have  been 
worn  out  during  this  period.  They  are  gorges  cut  in  the 
solid  rock,  sometimes  to  the  depth  of  a  mile.  For  days 
the  adventurer  may  travel  along  the  brink  of  such  a  gulf, 
unable  to  cross  or  to  descend  to  the  water  which  winds 
along  so  far  below,  at  the  bottom  of  the  appalling  chasm. 

2 .  2'he  IsOess  (Lo-ess,  from  the  German  Tosz^  loam). 
— The  alluvial  deposits  along  the  banks  of  rivers   are 
"generally  composed  of  coarse  materials  at  the  lowest  por- 
tions, and  fine  loam  (silt)   in  the  higher.     Where,  the 
current  is  strongest,  coarse  gravel  is  borne  along,  and 
where  weakest,  onjy  sand  or  mud.     A  thin  film  of  this 
line  sediment  is  spread  during  floods  over  wide  areas  on 
either  bank  of  the  stream.     The  well-known  deposits  of 
the  River  Nile,  to  which  Egypt  owes  its  fertility,  are  of 
this  character.     The  aggregate  during  a  century  is  said 
rarely  to  exceed  five  inches,  though  in  all  it  has  attained 
a  vast  thickness. 

Along  the  valley  of  the  Rhine  similar  deposits  of  loam 
have  taken  place  to  a  depth  of  many  hundred  feet.  The 
color  is  of' a  yellowish  gray,  the  structure  very  homoge- 
neous, and  the  composition  like  tnat  of  the  Nile.  Shells 
most  perfectly  preserved,  whose  fragility  is  too  great  to 
endure  the  rushing  of  a  stream  of  water,  are  quite  abun- 
dant. 

3.  Bluff  Formation.—  This  Loess  or  "Bluff  For- 
mation" (Swallow)  extends  to  a  great  distance  along  the 
lower  Missouri,  and  often  lines  its  branching  rivers.     It  is 


238  THE 'AGE    OF  MAMMALS. 

very  conspicuous  at  Sioux  City,  Council  Bluffs,  etc.  On 
the  Mississippi  it  reaches  from  the  junction  of  the  Mis-  • 
souri  to  the  delta,  forming  in  the  State  of  Mississippi  a 
belt  ten  or  fifteen  miles  wide,  and  often  seventy  feet  deep 
(Hilgard).  The  color  is  a  buff,  and  its  composition  a 
siliceous  loam.  The  shells  belong  to  existing  species, 
while  the  remains  of  mammoth,  horse,  lion,  musk-ox, 
etc.,  are  of  extinct  species.  We  thence  conclude  that  the 
physical  changes  which  resulted  in  the  destruction  of  the 
land  animals  did  not  extend  to  the  inhabitants  of  fresh 
water.  Foster  thinks  that  the  formation  is  a  lacustrian 
one,  and  that  when  it  was  deposited,  the  land  was-  de- 
pressed a  couple  of  hundred  feet  below  its  present  level. 

4 .  Sand  1)unes*  are  hills  of  sand  heaped  up  along 
the  shore.  They  are  formed  by  sand  drifted  inland  by 
the  wind,  as  snow  is  piled  in  drifts.  The  sand  is  driven 
with  such  force  as  to  smooth  the  surface  even  of  quartz 
rocks,  and  to  wear  holes  in  window-glass.  The  sand- 
dunes  of  Cape  Cod,  Long  Island  shore,  Lake  Michigan, 
etc.,  are  conspicuous  features  of  the  landscape.  Some- 
times long,  narrow  sand-ridges,  or  Osars,  extend  back 
from  the  shore  for  miles. 

5-.  The  Mosaic  Account  states  that  on  the  fifth 
day  the  waters  brought  forth  abundantly  the  moving 


*  On  the  east  side  of  Cape  Cod,  clearly  marked  -in  many  places  on  the  beach 
between  Provincetown  and  Truro,  the  former  shore-line,  of  the  west  side  may  be 
distinctly  traced.  The  whole  mass  of  sand  forming  that  part  of  the  cape  has 
been  carried  over  westward  into  the  bay.  This  movement  is  still  going  on,  and 
threatens  to  destroy  the  harbor  of  Provincetown.  Parties  of  men  have  therefore 
been  employed  by  the  United  States  government  to  set  out  beach-grass  along 
the  coast.  This,  by  the  extension  and  interlacing  of  its  fibrous  roots,  tends  to 
hold  the  sand  in  place.— Burbank. 


THE    POST-TERTIARYPERIOD. 

creature  that  hath  life,  the  fowl  that  flies  above  the  earth, 
and  great  whales.  The  sixth  day  was  characterized  by 
two  works — the  creation  of  mammals,  and  lastly  of  man, 
to  be  the  lord  of  all  created  things. 

Geology  gives  us  the  same  general  outline.  In  the 
Palaeozoic  Age,  the  seas  swarmed  with  life.  In  the  Meso- 
zoic  Age,  birds  appeared,  while  reptiles  (styled,  in  popular 
language,  great  whales  or  sea-monsters,  as  the  word  may 
be  translated)  became  the  dominant  life.  In  the  dawn 
of  the  Cenozoic,  mammals  of  enormous  size  and  in  pro- 
digious numbers  covered  the  earth;  while  at  the  close, 
Man  appeared  to  crown  the  creative- work. 

SGSITIC  DSSGRIPTIOIT.-This  glimpse  of  Ter- 
tiary  times  presents  a  scene  of  sylvan  beauty.  Before 
us  is  a  broad  meadow  carpeted  with  grass  and  blooming 
flowers,  while  behind  are  mountains  clad  in  forests  of 
familiar  trees.  In  the  foreground  is  a  lake  stretching 
away  in  the  distance  far  as  the  eye  can  reach,  its  waves 
sparkling  in  the  noontide  sun.  Snipes  make  their  retreat 
among  the  reeds  which  line  the  low  marshy  shore ;  .sea- 
gulls skim  the  water ;  owls  hide  themselves  in  the  trunks 
of  old  cavernous  trees ;  gigantic  buzzards  hover  threaten- 
ingly in  the  air,  poised  for  prey ;  great  turtles  crawl  up 
the  bank;  heavy  crocodiles  drag  their  unwieldy  bodies 
through  the  high  marshy  grass ;  and  a  huge  rhinoceros 
wallows,  grunting,  in  the  mud.  .  Over  the  plain  gallops 
a  troop  of  wild  horses ;  foxes  scamper  through  the  bushes ; 
and  .flocks  of  birds  sing  in  the  branches  of  the  willows 
that  border  a  neighboring  brook.  Everywhere  wander 
great,  unwieldy  quadrupeds.  Here  is  a  solitary  megathe- 
rium— a  gigantic  sloth — standing  on  his  massive  hind- 


£4®  TH:s    'AGE    OF    MAMMALS. 

legs,  and  propped  up  by  his  huge  tail,  which  makes  a 
secure  tripod  support.  See,  he  slowly  reaches  out  his 
muscular  arms,  draws  down  branches  and  young  trees, 
and  lazily  feeds  on  their  tender  foliage.  Yonder  is  a  herd 
of  mammoths  with  long  curved  tusks,  broad  flapping 
leathern  ears,  large  as  a  blacksmith's  apron,  and  legs  like 
fleshy  pillars.  Now  they  feed  along  the  bank,  now  they 
trumpet  shrilly  to  their  companions  in  the  forest,  whose 
responses  sound  like  distant  thunder,  and  now  they  go 
crashing  through  the  woods,  tearing  down  trees  for  sport, 
and  leaving  the  limbs  strewn  over  the  ground,  as  if  a 
hurricane  had  passed.  Fierce  beasts  abound.  A  drove 
of  wild  oxen  of  colossal  strength,  maned  and  shaggy, 
feed  over  the  meadow,  and  troops  of  hyenas  prowl  about, 
waging  relentless  war  on  all  weaker  tribes.  Hark !  the 
yelping  of  dogs!  A  pack  of  hounds  out  on  a  hunt.  The 
herd  of  wild  horses  catch  the  dreaded  sound,  snort  with 
fear,  toss  their  manes,  and  go  flying  off  like  the  wind, 
with  their  gaunt  pursuers  in  full  chase.  Scarcely  have 
they  disappeared  than  a  drove  of  camels  stalk  deliberately 
down  to  the  water's  edge,  and  while  they  drink  (as  only 
camels  can),  a  troop  of  monkeys,  chattering  in  the 
branches  overhead,  with  solemn  grimaces,  mock  the  grav- 
ity of  their  slow,  awkward  movements. 


p-1) 

' 


Geology,    which    is   the    story  of  the    rocks,  finds  its  climax  in 
History,  which  is  the  story  of  Man. 


/ 

. 

•'• 


- 


I  1 


Coming  of  Jlfan .  — We  have  no  means  of  de- 
ciding the  exact  time  when  the  human  race  first  appeared 
on  the  earth.  The  most  scientific  man  is  unable  to  name 
centuries  or  years  with  any  degree  of  accuracy  in  connec- 
tion with  any  geological  event.  In  the  loam  (Loess), 
peat-bbg  and  cave-earth  of  the  Post-Tertiary  Period  we 
first  find  rude  stone  implements,  tree  canoes,  and  the 
embers  of  the  fire  which  man  alone  can  kindle  or  sus- 
tain. Side  by  side  with  these  are  the  remains  of  the 
mammoth,*  cave -bear,  rhinoceros,  Irish  elk,  etc.  It 
would  seem  that  about  the  time  of  the  glacial  epoch, 
probably  just  as  the  great  ice-floats  began  to  melt  away, 
man  suddenly  appeared  among  the  mighty  quadrupeds 
which  then  covered  the  earth,  to  contest  the  supremacy, 

The  "Primeval  Man .  — The  life  of  the  pre-historic 
man  has  been  classified  according  to  the  character  of  the 


*  In  the  valley  of  the  River  Sorame,  near  Abbeville,  flint  implements,  associ- 
ated with  remains  of  the  mammoth,  elephant,  hippopotamus,  rhinoceros,  etc., 
were  found  by  M.  Boucher  de  Perthes.  Near  Amiens,  in  the  same  valley,  another 
deposit  of  gravel  was  discovered,  containing  flint  hatchets,  poniards,  knives, 
etc.,  nearly  400  in  number,  accompanied  also  by  bones  of  the  above  animals. 


THE     ERA     OF    MIND. 


fossil  remains  in  the  following  manner.    (Saint-Germain, 
Vogt,  and  others.) 


THE  STONE  AGE.   < 


II.  THE  METAL  AGE. 


1.  Epoch  of  extinct  animals,  mam- 

moth, cave-bear,  etc. 

2.  Epoch  of  migrated  existing  ani- 

mals, or  Reindeer  Epoch. 

3.  Epoch  of  domesticated  animals, 

or  Polished  Stone  Epoch. 

1.  The  Bronze  Epoch. 

2.  The  Iron  Epoch. 


These  terms  indicate  the  successive  progress  of  the 
ancient  races.  Every  nation  seems  to  have  had  some 
such  stages  in  its  advance.  The  Indians  have  hardly 
passed  out  of  their  stone  age.  The  Sandwich  Islanders, 
when  discovered,  were  in  that  age,  while  the  nations  of 
Asia  emerged  from  it  long  before  the  Christian  era. 
Some  of  these  ages  may  have  been  contemporaneous  in 
different  nations. 


HE 


TONE 


GE, 


JZpoch  of  IZxlinct  Animals. — The  primeval  man 
during  this  epoch  dwelt  in  caves,  dressed  in  skins,  and 
FIG.  113.  made    weapons    chipped 

out  of  the  rough  flint 
(Fig.  113),  by  means  of 
which  he  fought  the  cave- 
bear,  hunted  the  Irish 
A  Danish  Axe-hammer.  elk,  and  speared  the  mam- 

moth.    He  was  rude  and  barbarous,  perhaps  a  cannibal, 


THE     STONE     AGE. 


FIG.  114. 


yet  he  made  fire,  instruments  of  offence^  and  defence, 
articles  of  pottery-ware 
for  domestic  use  (Fig. 
114),  sewed  skins  into 
garments,  adorned  his 
person  with  strings  of 
rudely  -  carved  shells, 
wrought  out  images 
emblematic  of  his  po- 
litical or  religious  views, 
and  buried  his  dead  in 
caves  with  religious  rites 
and  ceremonies.* 


Reindeer  Epoch . 
— In  this  epoch  man 
advanced  in  knowledge,  learned  to  work  in  bone,  ivory, 


Earthen  Vase  found  in  Cave  of  Furfooz 
(Belgium). 


*  In  1842,  on  the  elope  of  a  hill  near  Aurignac,  an  excavator,  named  Bonne- 
maison,  discovered  a  great  vertical  slab  of  limestone  covering  an  arched  open- 
ing. In  the  cave  thus  closed  up  he  found  the  remains  of  seventeen  human 
skeletons.  These  were  removed  to  the  village  cemetery,  and  thus  lost  to  science 
forever.  In  1860,  M.  Lartet,  having  heard  of  the  event,  visited  the  spot,  which, 
during  a  long  course  of  centuries,  had  entirely  escaped  the  notice  of  the  inhabit- 
ants. The  entrance  to  the  cave  was  concealed  by  masses  of  earth,  which, 
having  been  brought  down  from  the  top  of  the  hill  by  the  action  of  water, 
had  accumulated  in  front,  hiding  a  flat  terrace,  on  which  many  vestiges  of  pre- 
historic times  were  found.  As  no  disturbance  of  the  ground  had  taken  place  in 
this  spot  subsequent  to  the  date  of  the  burial,  this  gradual  accumulation  had 
protected  the  traces  of  these  primeval  men.  The  investigations  of  M.  Lartet 
were  attended  with  the  following  results  :— 

He  found  on  the  floor  of  the  cave  a  bed  of  "  made  ground  "  two  feet  thick. 
In  this  were  some  human  remains  which  had  escaped  the  first  investigations ; 
also  bones  of  mammals  well  preserved,  and  exhibiting  no  fractures  or  teeth- 
marks,  wrought  flint-knives,  carved  reindeer  horns,  and  eighteen  small  eea- 
ehells  pierced  in  the  center,  and  doubtless  intended  to  be  strung  together  in  a 
necklace  or  bracelet.  He  found  also  a  quantity  of  the  bones  of  the  cave-bear, 
the  bison,  the  reindeer,  the  horse,  etc.  The  perfect  state  of  preservation  of 
these  bones  shows  that  they  were  neither  broken  to  furnish  food  for  man  nor 
torn  by  carnivorous  animals,  as  is  seen  in  many  cases.  It  must  be  concluded, 


246 


THE     ERA      OF     MIND. 


FIG.  115. 


Bone  pierced  by  an  Arrow  of  Reindeer-horn. 


and  reindeer-antlers  (Fig.  115) ;  to  catch  fish ;  to  make 
saAVS,  knives,  and  other  tools;  to  form  amulets  and 

charms  of  bone;  to 
ornament  the  in- 
struments of  the 
chase;  and  in  his 
leisure  to  sketch  on 
ivory  the  outlines  of 
the  animals  he  pur- 
sued (Fig.  116). 

'Polished  Stone 
JZpoch .  — The  next 
epoch  witnessed  a 
still  higher  condition.  Skiffs  were  made  in  which  the 
primitive  man  ventured  out  on  the  sea,  and  caught  the 
fish  of  deeper  waters.*  He  made  nets  for  fishing  near  the 

then,  that  the  stone  which  closed  the  entrance  to  the  cavern  was  moved  away  for 
every  interment,  and  carefully  put  back  immediately  afterward.  In  explaining 
the  presence  of  so  many  foreign  objects  in  the  burial-cave,  we  must  admit  as 
probable  that  the  customs  which  now  exist  among  savage  tribes— such  as  plac- 
ing near  to  the  dead  body  the  weapons,  hunting-trophies,  and  ornaments  be- 
longing to  the  deceased — existed  among  the  men  of  the  great  bear  and  mammoth 
epoch.  In  front  of  the  cave  was  also  found  the  site  of  an  ancient  fire-hearth, 
where  evidently  the  funeral  banquet  was  held.  In  this  bed  of  ashes  and  char- 
coal an  immense  quantity  of  the  most  interesting  relics  were  discovered— a 
large  number  of  teeth  and  broken  bones  of  herbivorous  animals ;  a  hundred 
flint-knives  ;  two  chipped  flints,  which  are  believed  to  be  sling  projectiles ; 
several  implements  made  of  reindeer's  horn,  etc.,  etc.  Some  of  the  bones  were 
partly  carbonized,  others  only  scorched,  but  the  greater  number  had  been  un- 
touched by  fire.  All  the  marrow  bones  were  broken  lengthwise,  showing  that 
they  had  been  used  at  a  feast  where  the  marrow  from  animal  bones  furnished  a 
delicious  viand.  Traces  of  the  hyena  were  found  at  this  spot.  From  all  these 
signs  we  infer  that  after  the  death  of  one  of  these  primitive  men,  his  friends 
accompanied  him  to  his  last  resting-place,  after  which  they  assembled  together 
to  partake  of  a  feast  in  front  of  his  tomb  ;  then  every  one  took  his  departure, 
leaving  the  scene  of  the  banquet  free  to  the  hyenas,  which  came  to  devour  the 
remains  of  the  meal. 

*  Along  the  coast  of  Denmark,  in  Cornwall  and  Devonshire,  England,  in 
Scotland,  and  e\:en  in  France,  have  been  discovered  what  have  received  the 


THE     METAL      AGE. 

shore.     He  domesticated  the  dog.     He  attempted  agri- 
Fro.  116. 


Sketch  of  a  Mammoth  graven  on  a  Slab  of  Ivory. 

culture;  raised  corn,  ground  it,  and  thus  became  less 
dependent  on  the  chances  of  the  chase.  He  interred 
his  dead  in  vaults,  and  erected  monuments  to  mark 
their  last  resting-place.  (See  Fig.  117). 


name  of  "kitchen-middens."  They  are  immense  accumulations  of  shells  from 
3  to  10  feet  in  thickness,  and  from  100  to  200  feet  in  width  ;  their  length  is  some- 
times as  much  as  1,000  feet,  with  a  width  of  250  feet.  At  first  seeming,  one 
would  think  them  banks  of  fossil  shells  which  had  been  submerged,  and  after- 
ward volcanically  brought  to  light.  But  it  has  been  discovered  that  these  shells 
belong  to  four  different  species  which  are  never  found  together,  and  conse- 
quently must  have  been  brought  there  by  man.  Nearly  all  the  shells  are  those 
of  full-grown  animals.  Also  traces  of  fire— remains  of  hearths— were  found  in 
these  heaps,  which,  with  the  other  facts,  lead  to  one  conclusion.  Tribes  once 
existed  there  who  lived  on  the  products  of  hunting  and  fishing,  throwing  out 
round  their  cabins  the  remains  of  their  meals,  especially  the  debris  of  shell-fish. 
Hence  the  name,  which  signifies  "  kitchen  heaps  of  refuse."  Nearly  all  these 
kitchen-middens  are  found  on  the  coast,  along  the  fiords,  where  the  action  of  the 
waves  is  not  much  felt.  Some  have  been  found  inland;  but  this  proves  that 
the  sea  once  occupied  those  localities  from  which  it  has  now  retired.  These 
refuse  deposits  consist  mostly  of  various  shells  of  mollusks — such  as  the  oyster, 
the  cockle,  the  mussel,  and  the  periwinkle.  Fishes'  bones,  in  great  abundance, 
are  also  found.  They  belong  to  the  cod,  herring,  dab,  and  eel.  From  this  we 
may  infer  that  the  primitive  inhabitants  ventured  far  out  to  sea,  as  the  herring 
and  cod  can  only  be  caught  at  some  distance  from  shore.  The  remains  also  of 
the  stag,  the  roe,  the  boar,  and  various  other  mammals  are  discovered,  with 
some  traces  of  birds— mostly  aquatic  species.  All  the  long  bones  are  found  split 
to  extract  the  marrow. 


THE     ERA      OF     MIND, 

FIG.  117. 


Row  of  Menhirs  or  Monuments  set  up  on  Tombs  at  Carnac,  Brittany. 


HE 


ETAL 


GE. 


This  age  indicates  a  great  advance  in  civilization. 
Thenard  asserted  that  we  may  judge  of  the  civilization  of 
any  nation  by  the  degree  of  perfection  it  has  attained  in 
working  iron.  We  may  safely  say  that,  without  a  knowl- 
edge of  the  metals,  man  would  have  remained  a  barbarian. 
Iron  ores  do  not  readily  attract  attention,  and  their  re- 
duction is  a  very  difficult  process.  The  method  whereby 
iron  becomes  utilized  in  the  arts,  requires  extensive  chem- 
ical knowledge  and  high  progress  in  science.  Gold,  how- 


THE     METAL     AGE. 


ever,  is  found  native,  and  by  its  glitter  attracts  the  eye 
even  of  the  savage.  Copper  occurs  pure,  and  its  ores  are 
rather  widely  diffused,  as  are  'also  those  of  tin.  It  is 
strange  that  bronze  (brass),  which  is  an  alloy  of  copper 
and  tin,  should  have  been  the  first  metal  used.  We  can 
hardly  understand  the  cause  of  this,  since  the  metals 
must  have  been  known  before  the  alloy  could  be  manu- 
factured. 

Bronze  JZpoch .  — Tools  of  a  better  character  were 
now  made,  and  life  wore  an  improved  aspect.  Extensive 
villages  were  built  on  piles*  driven  deep  in  the  lake- 


*  The  discovery  of  the  remains  of  lake-dwellings  in  Switzerland,  and  their 
connection  with  the  bronze  epoch— as  first  asserted  by  Dr.  Keller,  of  Zurich,  and 
eince  agreed  to  by  all  archaeologists— reveal  to  us  many  very  interesting  facts  in 
regard  to  the  pre-historic  natives  of  that  country.  When,  in  the  dry,  cold  winter 
of  1853-1854,  the  waters  of  the  lakes  in  Switzerland  fell  so  far  below  their  ordi- 
nary level,  the  inhabitants  of  Meilen,  on  the  banks  of  Lake  Zurich,  thus  gaining 
from  the  lake  a  tract  of  ground,  set  to  work  to  raise  it  and  surround  it  with 
banks.  In  carrying  out  this  work  they  found  in  the  mud  at  the  bottom  of 
the  lake  a  number  of  piles,  some  thrown  down  and  some  still  upright,  frag- 
ments of  rough  pottery,  bone  and  stone  instruments,  and  various  other  relics 
similar  to  those  found  in  the  Danish  peat-bogs.  Previous  to  this,  various  instru- 
ments and  strange  utensils  had  been  obtained  from  the  mud  of  some  of  the 
Swiss  lakes,  and  piles  had  often  been  noticed  standing  up  in  the  water,  but  no 
one  had  thought  of  attributing  any  great  antiquity  to  these  objects,  or,  indeed, 
made  much  attempt  to  explain  them.  The  fishermen  had  for  some  time  been 
acquainted  with  the  sites  of  some  of  these  lake  settlements,  in  consequence  of 
having  often  torn  their  nets  on  the  piles  sticking  up  in  the  mud.  Thus, 
guides  were  at  hand  to  aid  in  searching  out  the  mystery  of  these  lake  abodes. 
More  than  200  settlements  are  already  known,  and  every  year  fresh  ones  are 
being  found.  The  builders  of  these  lacustrine  dwellings  seem  to  have  pro- 
ceeded  on  two  different  systems  of  construction :  either  they  buried  the  piles 
very  deeply  in  the  bed  of  the  lake,  and  on  them  placed  the  platform  which  was 
to  support  their  huts,  or  they  artificially  raised  the  bed  of  the  lake  by  means  of 
heaps  of  stones,  fixing  in  them  large  stakes  to  make  a  firm  and  compact  body. 
Sometimes  these  are  so  high  as  to  rise  above  the  water,  and  form  artificial 
islands ;  and  some  of  them  are  still  inhabited. 

We  may  reasonably  suppose  that  need  for  security  prompted  the  ancient 
people  to  thus  construct  their  dwellings  over  the  water.  Encompassed  by  vast 
marshes  and  impenetrable  forests,  no  means  could  so  effectually  secure  them 
from  the  attacks  of  wild  beasts  as  to  surround  themselves  with  water.  In  later 


THE     ERA      OF    MIND. 


FIG.  118. 


Woolen  Shawl  found  in  a  Tomb  in  Denmark. 


bottom,  looms  were  erected,  cloth  was  woven  and  made 
into  garments  (Fig.  118).  The  horse,  ass,  ox,  sheep  and 

goat  were  domestica-  ' 
ted  in  great  numbers. 
Hatchets,  reaping- 
hooks,  mills,  peiid- 
\ants,  rings,  li air-pins, 
barbed  fish  -  h  ooks, 
and  numerous  arti-* 
cles  of  ornament  were 
manufactured  (fig. 
119).  The  clothing 
became  more  'grace- 
ful, and  the  hair  was 
adorned  with  the 
most  elaborate  taste. 

Wheat,  barley  and  oats  were  cultivated.  The  baker's  art 
was  established.  Glass  was  discovered.  Mats  of  bark  and 
cord  were  made.  Apples,  pears,  berries,  and  other  fruits 
were  stored  for  winter's  use. 

Iron  JZpocfi. — With  the  discovery  of  iron,  civiliza- 
tion rapidly  advanced.  This  metal  marked  the  latest 
period  of  primeval  development.  The  art  of  metallurgy 

times  it  served  to  protect  them  from  sudden  surprises  by  their  enemies  of 
other  clans.  The  number  of  piles  used  in  these  constructions  is  surprising. 
They  were  often  sixteen  or  twenty  feet  long,  and  in  the  stone-heaps  were  some- 
times ten  or  twelve  inches  in  diameter."  The  mind  is  almost  confused  when  it 
endeavors  to  sum  up  the  amount  of  energy  and  strong  will  which,  without  the 
aid  of  iron  implements,  must  have  been  bestowed  in  constructing  these  settle- 
ments. One  of  the  largest,  that  of  Morges,  in  Lake  Geneva,  is  71,000  square 
yards  in  area.  The  huts  themselves  seem  to  have  been  formed  of  trunks  of 
trees  placed  upright  side  by  side,  and  bound  together  by  interwoven  branches. 
A  coating  of  earth  covered  this  wattling.  Some  of  these  huts  having  been  par- 
tially destroyed  by  fire,  among  the  charred  debris  various  articles  have  been 
perfectly  preserved,  such  as  fishing-nets,  basket-work,  corn,  etc. 


THE     JIE  TA  L     A  G  11. 


251 


FIG.  119. 


had  made  great  progress  during  the  bronze  epoch,  but 
now  assumed  nev»  importance.  Extensive  smelting  works 
were  erected.*  The  potter's 
wheel  was  invented.  Better 
tools  were  made  (Fig.  120). 
Silver  and  lead  were  discov- 
ered. Coined  money  was  in- 
troduced and  commerce  flour- 
ished (Fig.  121).  Agriculture 
was  practiced  on  a  large  scale, 
Fruit  trees  were  cultivated. 
Civilization  was  fairly  es-  . 

•*  Bronze  Vase  from  the  lomb  of  Hallstadt. 

tablished.     At  this  point  the 

written  records  and  oral  traditions  take  up  the  story  of 
the  past,  and  the  naturalist's  labors  cease  as  the  histo- 
rian's begin. 

FIG.  120. 


Knife  from  the  Lacustrine  Settlements  of  Switzerland. 


FIG.  121. 


The  ^Development  2' heavy. — This  primeval  man 
shows  no  sign  of  a  development  from  the 
higher  tribes  of  animals.  He  is  not  a 
perfected  monkey.  "  No  gorilla  ever 
took  out  a  patent."  No  ape  ever  made 
any  improvement  on  the  condition  in 
which  he  was  born.  Man,  on  the  other 
hand,  never  stays  where  he  starts.  He 

*  Four  hundred  iron  furnaces  have  been  discovered  by  M.  Quiqucrez  in  the 
Bernese  Jura. 

/~> 


852  THE    ERA      OF    MIND. 

continually  progresses.  The  very  names  given  to  the  vari- 
ous ages  and  epochs  of  his  primeval  history  in  Europe  in- 
dicate this  fact.  He  appears  among  those  huge  quadru- 
peds whose  figures  stalk  like  mighty  shadows  across  the 
scenes  of  the  Post-Tertiary  Period,  and  is  at  once  their 
lord  and  master.  He  uses  the  bow  and  spear.  He  be- 
comes a  builder  and  inventor.  He  makes  tools,  subdues 
the  earth,  hews  down  the  forest,  bridges  the  river,  builds 
houses,  tames  wild  animals  and  converts  their  strength  to 
his  purposes,  while  from  every  element  of  Nature  he 
gathers  material  for  use  and  beauty.  Lastly  and  best  of 
all,  he  buries  his  dead  with  religious  ceremonies,  in  care- 
fully constructed  tombs,  and  deposits  in  their  graves  arms 
and  food  for  their  journey  to  the  spirit-land.  (Vogt.) 
His  thought  reaches  out  into  the  life  beyond,  and  he  be- 
trays at  once  the  longings  of  an  immortal  soul. 

(Geologyjgives  us  no  means  of  answering  that  oft-asked 
question,  whether  there  was  one  or  were  many  centers  of 
man's  creation.  As  far  as  the  facts'  go,  however,  the 
sameness  of  the  remains,  wherever  found,  evinces  a  simi- 
larity of  ideas,  and  thus  tends  to  prove  a  common  origin 
for  the  race.  Those  who,  disregarding  the  unity  of  lan- 
guage, of  mental  constitution,  and  of  the  religious  senti- 
ment of  the  human  race,  desire  to  show  that  the  Mosaic 
account  is  only  a  partial  and  inaccurate  one,  must  look 
for  arguments  elsewhere  than  in  the  records  of  geology.  , 

Geological  2'heories. — Many  of  the  geological 
theories  we  have  discussed  may  be  set  aside  by  future 
discoveries,  and  be  proved  to  have  been  vain  assumptions. 
They  will  yet,  however,  have  served  a  purpose.  The 
mind  instinctively  demands  order.  Each  theory  is  a  cord 


THE     METAL     AGE. 

on  which  to  string  facts  that  otherwise  might  be  lost. 
Theories  are  generalizations  of  truth.  They  give  consist- 
ency and  interest  to  a  science  that  otherwise  would  be 
only  a  mass  of  discordant  and  uninviting  detail.  Our 
theories  may  yet  be  thrown  away,  but  our  facts  never, 
and  we  can  but  be  grateful  for  the  former  in  that  they 
have  helped  us  to  retain  the  latter. 

2*he  'World  Uiifinished.  —  Creation  is  continually 
going  on  around  us.  Astronomy  teaches  that  the  stars 
are  changing — new  ones  flashing  out  in  the  sky  and 
others  fading  away  into  darkness.  Geology  did  not  cease 
when  history  began.  Since  the  coming  of  man,  vast 
physical  changes  have  taken  place.  The  mastodon  and 
Irish  elk  vanished  with  his  first  appearance.  The  dodo 
of  Mauritius  is  known  only  by  tradition.  The  animals 
of  the  present — the  ostrich,  beaver,  etc. — are  hastening  to 
extinction.  The  mud  and  sands  of  our  sea-shore  will  be 
the  rocks  of  future  hills,  and  the  rocks  of  our  hills  the 
ocean  sediment  of  another  age.  Rivers  have  deserted 
their  old  channels;  the  ocean  has  encroached  on  the 
land ;  *  lakes  and  marshes  have  disappeared ;  volcanoes 


*  There  is  abundant  evidence  to  show  a  slow  subsidence  of  the  whole  eastern 
coast  of  the  United  States,  which  has  been  going  on  for  several  years  past.  The 
movement  is  one  of  alternate  elevation  and  depression  within  the  limits  of  per- 
haps twenty  feet.  A  map  of  Cape  May,  dated  1694,  shows  Egg  Island  as  contain- 
ing  200  acres ;  it  now  contains  less  than  an  acre  at  ebb  tide,  and  is  entirely 
submerged  at  high  tide.  The  light-house  at  the  Cape  has  been  moved  consider- 
ably inland  on  account  of  the  wear.  The  shore  in  front  of  the  boarding-houses 
at  Cape  Island  must  have  worn  away  neatly  a  mile  since  the  Revolution.  Dur- 
ing the  war  of  that  period,  a  militia  artillery  company  had  its  practicing  ground 
here.  Their  gun  was  placed  near  a  house  which  stood  just  outside  the  present 
shore-line,  and  their  target  was  set  up  at  the  outer  side  of  a  corn-field,  three- 
quarters  of  a  mile  cast.  Beyond  this  there  were  sand-beaches  for  nearly  or  quite 
a  quarter  of  a  mile,  and  then  the  sea-shore.  The  whole  of  this  ground  is  now 
gone,  and  one  of  the  boarding-houses  has  been  moved  back  twice.  Sandy  Hook 
has  extended  out  to  the  northeast  a  mile  since  the  Revolution.  The  spot  where 


THE      ERA       OF     MIND. 


have  thrown  out  rivers  of  lava,  and  earthquakes   have 
cracked  the  earth's  crust. 

"  There  rolls  the  deep  where  grew  the  tree  ; 
O  earth,  what  changes  hast  thou  seen  ! 
There,  where  the  long  street  roars,  hath  been 
Tho  stillness  of  the  central  sea."  —  Tennyson. 

The  Origin  of  Man.  —  Was  man  created  directly 
by  God's  fiat,  or  by  some  intermediate  process  of  second- 
ary causes  ?  "Alas  for  the  impotence  of  science  and  the 
scope  of  our  finite  intelligence!"  We  bring  the  subtlest 
agencies  to  the  accomplishment  of  our  designs  —  Heat, 
Light,  Electricity  —  but  when  we  seek  to  develop  from 
them  even  the  intangible  forces  which  clothe  the  decay- 
ing rock  with  verdure,  or  mantle  the  stagnant  pool  with 
slime,  failure  inevitably  waits  upon  us.  In  vain  do  we 
seek  to  associate  vital  manifestation  with  electrical  action  ; 
we  may  resolve  the  vital  organism  into  cells  and  granules 
and  nuclei,  but  the  life  eludes  our  proudest  philosophy. 
If,  under  certain  conditions,  inorganic  matter  assumes 
organic  form,  those  conditions  and  the  laws  which  gov- 


the  first  boarding-house  was  erected  at  Long  Branch,  together  with  the  road 
behind  it,  is  now  all  worn  away.  The  loss  is  sometimes  twelve  feet  in  a  year. 
Where  seventy  years  ago  were  cultivated  fields  is  now  the  ship-channel.  At 
several  points  in  New  Jersey  an  enormous  quantity  of  white  cedar  is  found 
buried  in  the  salt  marshes.  This  indicates  extensive  forests  on  land  now  too 
low  and  wet  for  the  growth  of  trees.  Trunks  are  found  sunk  at  all  depths  down 
to  the  underlying  gravel,  and  so  thick  that  in  many  places  a  number  of  trials 
must  be  made  before  a  sounding-rod  can  be  thrust  down  without  striking 
against  them.  Tree  after  tree  from  one  to  two  thousand  years  of  age  lies  crossed 
above  each  other  in  every  conceivable  direction.  These  cedar  logs  are  mined 
and  split  into  shingles,  and  thus  is  carried  on  a  very  extensive  business.  Sub- 
marine forests  exist  on  the  shore  of  Martha's  Vineyard  and  also  at  Rye  Beach. 
All  along  the  sea-coast,  from  South  Carolina  to  Florida,  similar  phenomena  are 
to  be  found  which  seem  to  indicate  a  subsidence  of  the  laud.^-iSee  Cook's  Geology 
Of  New  Jersey,  PP-  343-373. 


CONCLUSION.  255 

ern  them  are  alike  unknown  to  us.  And  so  we  pause 
on  the  threshold  of  created  life,  and,  standing  reverently 
aside,  lay  humbly  down  our  little  wisdom  as  we  recog- 
nize the  unfathomable  greatness  of  the  ONE  ALL-WISE 
CREATOR. 

"  We  have  but  faith  :  we  cannot  know ; 
For  knowledge  is  of  things  we  see  ; 
And  yet  we  trust  it  C3mes  from  Thee, 
A  beam  in  darkness :  let  it  grow." 


%  0  N  C  L  U  S.  I  0  N  . 

We  have  traced  in  the  dim  light  of  the  past  the  his- 
tory of  our  earth  and  its  inhabitants.  Everywhere  we 
have  found  a  Divine  Hand  shaping  and  moulding  to 
accomplish  a  Divine  ideal.  "  IN  THE  BEGINNING  GOD." 
We  can  add  nothing  to  the  old  Hebrew  declaration.  We 
have  gone  back  to  the  origin  of  man,  and  there  too  we 
have  rested  on  that  sublime  truth,  "  IN  THE  BEGINNING 
GOD."  We  have  winged  our  imagination  backward  to  the 
.time  when  our  earth  was  "  without  form  and  void,"  and 
here  again  we  have  felt  the  force  of  that  same  statement — 
"  IN  THE  BEGINNING  GOD."  The  study  of  science  ought 
never  to  lead  one  astray  from  this  great  fundamental 
thought.  God  has  assuredly  never  written  anything  in 
Nature  contradictory  of  Himself!  Science  and  religion 
alike  are  His  offspring.  Both  will  ultimately  vindicate 
Him  and  His  attributes.  During  this  transitional  period 
they  may  oftentimes  seem  to  clash,  but  they  will  ulti- 
mately come  into  perfect  accord.  He  who,  even  now, 
from  an  elevated  point  surveys  the  contending  hosts  on 


THE     ERA     OF    MIND. 

this  fiercely-fought  field,  will  see  that  the  scientists  and 
the  religionists  are  fast  setting  out,  if  not  even  now 
moving  upon  converging  lines  of  thought.  By-and-by 
they  will  meet.  Forgetting,  then,  the  rancor  and  bitter- 
ness of  the  past  in  the  joy  of  newly-found  truth,  they 
will  clasp  hands,  and  together  cast  the  crowns  of  their 
triumphs — the  triumphs  of  Science  and  Christianity — at 
the  feet  of  their  common  Author,  and  God  shall  be  pro- 
claimed LORD  or  ALL! 


FIRST     PART. 

[Tke  figures  refer  to  the  pages  of  the  book.] 

INTRODUCTION. — State  the  origin  of  the  earth  according  to  the 
nebular  hypothesis.  Why  did  the  earth  assume  a  globular  form  ? 
Describe  the  appearance  of  the  first  crust.  The  first  rain.  Why 
was  the  water  hot  ?  What  was  the  effect  of  the  rain  ?  Describe  the 
conflict  between  fire  and  water. 

19.  Where  do  Astronomy  and  Geology  meet?    Meaning  of  the 
term  "day"  in  the  Scriptures?     Give  the  parallel  between  the  Mo- 
saic and  the  geologic  account. 

20.  Give  some  idea  of  the  appearance  of  the  earth  at  that  time. 
Define  Geology. 

21.  How  thick  is  the  earth's  crust?     How  deep  has  it  been  ex- 
amined?    Condition  of  the  interior?     Name  the  six  reasons  given 
to  prove  that  the  interior  is  a  melted  mass.     At  what  rate  does  the 
temperature  increase  as  we  descend  ?     Illustrate.     Name  some  ar- 
tesian wells  that  furnish  warm  water. 

22.  Name  some  geysers  that  throw  up  hot  water.     Cause  of  this 
difference  in  temperature?     Is  the  earth's   crust   steady?    What 
does  this  oscillation  show?     What  are  volcanoes?     How  many  are 
active?     Give  an  illustration  of  the  amount  of  lava  they  throw  out 
at  an  eruption.     Cause  of  volcanoes? 


258  QUESTIONS. 

23.  How  many  earthquakes  have  been  recorded  in  the  last  half 
of  a  century  ?     Cause  of  earthquakes  ?  *     State  in  what  respects  the , 
earth  is  a  microcosm.     In  what  way  is  the  present  to  the  geologist 
the  key  to  the  past  ? 

24-5.  By  what  course  of  reasoning  does  the  geologist  infer  that 
.certain  kinds  of  rocks  were  formed  by  water?  Are  rocks  now  being 
'made  in  this  way?  What  does  the  geologist  call  such  rocks: 
How  does  the  ocean  record  the  history  of  the  land? 

26.  Where  does  the  geologist  find  the  history  of  the  past  written? 
Has  the  ocean  always  been  where  it  is  now?     By  what  course  of 
reasoning  does  the  geologist  conclude  that  certain  rocks  have  been 
thrown  up  in  a  melted  state  from  the  interior  of  the  earth  ? 

27.  What  name  does  he  apply  to  such  rocks?     Can  he  be  mis- 
taken in  the  principle  ?     Define  fossils.     Give  some  illustrations  of 
the  mistakes  the  ancients  made  concerning  them.    Plater's  blunder. 
What  view  was  generally  held  at  a  later  day  ? 

28.  Describe  the  process  of  fossilization.     Are  fossils  now  being 
made  ?     When  we  find  a  fossil  bone,  what  conclusion  do  we  draw  ? 
How  can  a  geologist  restore  the  form  of  an  ancient  animal,  deter- 
mine its  habits,  etc.  ?  f 

*  In  the  text  the  theory  of  earthquakes  is  given  as  that  of  "  billowy  pulsations  " 
in  the  crust  resting  on  the  waves  of  a  lava-ocean.  Dana,  holds  that  they  are  pro- 
duced by  the  folding  up  of  the  rocks  in  the  slow  process  of  cooling  and  conse- 
quent contraction.  An  earthquake  Wave  consists,  as  in  all  wave-motion,  of  a 
progressive  vibration  as  well  as  a  vertical  oscillation  (Phil.,  p.  128).  The  upward 
vibration  seldom  exceeds  two  feet  in  height.  The  forward  movement  has  a  rate 
of  twenty  to  thirty  miles  per  minute,  depending  on  the  character  of  the  crust 
through  which  it  passes ;  in  the  "  undisturbed  beds  of  the  Mississippi  valley  the 
rate  being  greater  than  among  the  contorted  strata  of  Europe."  Orton  says  that 
no  familiarity  with  earthquakes  enables  one  to  laugh  during  the  shock,  or  even  at 
the  subterranean  thunders,  which  sound  like  the  clanking  of  chains  in  the  realm 
of  Pluto.  All  animated  nature  is  terror-stricken.  The  horse  trembles  in  his  stall. 
The  cow  moans  a  low,  melancholy  tune.  The  dog  sends  forth  an  unearthly  yell. 
Sparrows  drop  from  the  trees  as  if  dead.  Crocodiles  leave  the  trembling  bed  of 
the  river  and  run  with  loud  cries  into  the  forest.  When  the  earth  rocks  beneath 
our  feet,  we  feel  something  beside  giddiness.  "  A  moment,"  says  Humboldt, 
"  destroys  the  illusion  of  a  whole  life."  We  realize  an  utter  insignificance  in  the 
presence  of  that  mysterious  Power  that  guides  the  forces  of  Nature.  • 

t  "  Such  is  the  unity  and  persistence  of  plan  which  runs  through  the  different 
classes  of  the  animal  kingdom,  that  a  single  tooth,  whether  of  a  living  or  extinct 
species,  will  often  suffice  to  enable  the  expert  to  disclose  all  the  zoological  rela- 
tionships of  the  animal  to  which  it  belonged,  to  delineate  its  form,  and  size,  and 
habits  of  life  ;  as  the  architect  from  a  single  capital  rescued  from  a  ruined  edifice 


QUESTIONS.  259 

29.  Illustrate.     Why  does  a  geologist  think  a  fossil  shell  was 
once  inhabited  ?     What  does  the  shell  show  ?     What  proof  is  there 
that  an  Arctic  climate  once  existed  in  England  and  France?     Is 
this  good  reasoning  ? 

30.  What  reasons  has  the  geologist  for  thinking  that  certain  re- 
gions were  once  covered  with  glaciers  or  icebergs  ? 

31.  How  does  he  know  that  a  race  of  cave-dwelling  men  once 
lived   in    Europe?      That   they  were   contemporaneous   with   the 
hyena?     Describe  the  discoveries  that  could  be  made  in  digging 
through  an  old  lake-bottom. 

32.  Give  the  history  of  the  lake  as  deduced  from  such  data.    Can 
we  judge  of  the  antiquity  of  the  lake?     State  what  has  been  found 
in  draining  old  Scottish  lake-bottoms.     The  history  indicated  by 
these  remains. 

SECOND     PA  RT. 

LITHOLOGICAL  GEOLOGY. — Define.  Name  the  three  classes  into 
which  it  is  divided.  Define  the  term  "  rock." 

40.  What  common  minerals  compose  the  larger  part  of  the 
earth's  crust  ?  Properties  of  quartz ?  Its  tests? 

42.  Why  are  quartz  pebbles,  etc.,  so  abundant  ?  Size,  clearness, 
etc.,  of  quartz  crystals?  What  is  rock  crystal?  Why  so  called? 


can  declare  not  only  the  general  style  of  the  entire  architecture,  but  can  repro- 
duce the  size  and  proportions  of  the  temple  whose  spirit  and  method  it  embodies. 
Not  less  sublime  than  the  work  of  the  astronomer",  who  sits  in  his  observatory, 
and,  by  the  use  of  a  few  figures,  determines  the  existence  and  position  in  space 
of  some  far-off,  unknown  orb,  is  that  of  the  palaeontologist — the  astronomer  of 
time-worlds— who,  from  the  tooth  of  a  reptile,  or  the  bony  scale  of  a  fish  found 
thirty  feet  deep  in  the  solid  rock,  declares  the  existence,  ages  ago,  of  an  animal 
form  which  human  eyes  never  beheld — a  form  that  passed  totally  out  of  being 
uncounted  centuries  before  •  the  first  intelligent  creature  was  placed  upon  our 
planet — and  by  laws  as  unerring  and  uniform  as  those  of  the  mathematics,  pro- 
ceeds to  give  us  the  length  and  breadth  of  the  extinct  form  ;  to  tell  us  whether  it 
lived  upon  dry  land,  in  marshes,  or  in  the  sea ;  whether  a  breather  of  air  or 
water,  and  whether  subsisting  upon  vegetable  or  animal  food.  It  is  this  unity  of 
the  laws  of  animal  life  and  organization  running  through  .the  whole  chain  of  ex- 
istence, whether  past  or  present,  whether  extinct  or  recent,  that  constitutes  the 
sublime  philosophy  of  palseontological  studies,  and  assures  us  that  one  enduring 
and  infinite  Intelligence  has  planned  and  executed  every  part  of  creation."— 
Winchelfs  Sketches  of  Creation,  p,  175. 


260  QUESTIONS. 

Its  uses  ?     Illustrate  the  great  variety  of  forms  which  quartz  as- 
sumes.    Describe  rose  quartz. 

43.  Smoky  quartz.     Milky  quartz.    Granular   quartz.     Its  uses. 
Amethyst.      Why   so    called?      Chalcedony.       Carnelian.       Sard. 
Chrysoprase.     Agate.     Name  the  different  varieties  of  agate.* 

44.  What    is    a    cameo?      Describe    some    celebrated    antique 
cameos.     The  process  for  preparing  agates  for  the  market. 

45.  Describe  jasper.     Cause  of  its  color?     Name  and  describe 
the  different  varieties  of  jasper.     What  is  opal?     Its  appearance  ? 

46.  For  what    is   hydrophane   noted?     How  is   this  explained? 
What  gives  the  color  to  quartz  pebbles,  sand,  etc.  ?    Show  that  iron 
is  Nature's  universal  dye  !     Describe  flint.     Its  tests.     Hornstone. 
Buhrstone. 

47.  Cause  of  its  cellular  structure?     Origin  of  quartz?     What 
are  diatoms?     How  do  they  form  rocks  ? 

48.  What  is  tripoli  ?     Fossil  farina?     Infusorial  earth?     Noted 
localities  ?     Appearance  of  flint,  etc.,  under  the  microscope  ?  What 
conclusion  is    drawn   from   these   facts?     Describe   alumina.     Its 
tests. 

49.  Sapphire.     Corundum.     Emery.     Composition  of  limestone. 
Tests.     Lime.     Calcite.     Iceland  spar.     Its  test.     Chalk.     Calca- 
reous tufa.     The  Tiber  stone. 

50.  What  are  stalactites  ?     Stalagmites  ?    Appearance  of  Oolite  ? 
What  is  marl?     Its  uses?     Dolomite?     Its  test  ?    Marble? 

51.  Describe   the   Parian   marble.      Name   some  works   of   art 
wrought  from  this  stone.     How  is  the  quality  of  marble  often  in- 
jured?    What  is  verde-antique?     Describe  the  process  of  sawing 
marble.     Wherein  is  this  stone  especially  designed  for  man's  use  ? 

52.  Illustrate  the  abundance  of  limestone.    What  was  the  origin 
of  limestone  ?     Of  chalk  ?    What  does  the  abundance  of  limestone 
prove?    What  is  gypsum  ?     Its  tests?     Plaster?     Its  uses? 

53.  Forms  of  crystallized  gypsum?     A  noted  locality?     What  is 
plaster  of  Paris?    What  are  silicates?     Name  the  six  prominent 
ones.    Tests  of  feldspar.     Three  varieties  of  feldspar.    Their  tests. 
What  is  clinkstone?     Common  clay? 


*  The  peculiar  form  assumed  by  the  oxyd  of  iron  in  the  moss-agate  is  said  by 
microscopists  to  be  due  to  the  presence  of  tiny  fossil  sponges  in  the  stone. 


54.  Kaolin  ?      Why   are   bricks   red   and   tobacco-pipes   white  ? 
Common  name  for  mica?    Its  tests?     Its  uses?     In  what  forms  is 
it  found  ?     Describe  hornblende.     Why  so  called  ?     Asbestos.     Its 
uses. 

55.  Augite.      How   distinguished   from   hornblende?*      Talc.f 
Its  tests.     What  is  French  chalk  ?     Soapstone?     Uses? 

56.  What  is  serpentine  ?     Its  tests  ?    Why  so  called  ?    Its  uses  ? 
What  is  chlorite?     Garnet?     Its    tests?     Ancient   name?     Tour- 
maline ? 

57.  Name  the  three  general  classes  of  rocks.     Define  sedimen- 
tary rocks.     Name  the  four  divisions  of  sedimentary  rocks.     What 
is  sandstone?     Conglomerate?     A  siliceous  sandstone  ?    An  argil- 
laceous one  ? 

58.  Name  the  three  kinds  of  conglomerate.     What  is  a  pudding- 
stone  ?     A  breccia?     A  shale  ?     A  sedimentary  limestone  ?    What 
are  the  characteristics  of  the  landscape  in  a  sandy  region  ? 

59.  Define  igneous  rocks.    By  what  other  name  are  they  known? 
Into  what  two  classes  are  they  divided  ?   Describe  trap-rocks.  Why 
so  called  ?     Their  uses  ?     Name  the  four  varieties  of  trap-rocks. 
What  is  basalt  ?     Chrysolite  ?     Greenstone  ?     Common  name  ? 

60.  Describe  porphyry.     Why  so  called  ?    What  is  a  porphyritic 
rock  ?     An  amygdaloid  ? 

61.  What  form  does  trap  assume  in  crystallizing?     Causes  of 
this  ?     Noted  trappean  scenery  ? 


*  The  soft,  light-colored  pencils  in  common  use  are  made  from  a  soap-stone 
rock  found  at  Castleton,  Vt.  It  is  a  silicate,  technically  known  as  argillite.  This 
is  the  only  deposit  fit  for  pencils  as  yet  discovered  in  the  world.  The  rock  is 
blasted,  and  is  worked  immediately,  as  it  soon  becomes  hard  and  brittle,  and 
hence  useless.  The  stone  is  first  split  into  slabs  about  an  inch  thick,  and  then 
sawn  into  blocks  about  seven  inches  long  and  five  wide.  These  are  carried  to 
the  "  splitting  table,"  where  workmen,  with  a  hammer  and  a  bit  of  steel  like  the 
blade  of  a  knife,  split  them  into  little  plates  about  one-third  of  an  inch  thick. 
The  squares  are  now  of  a  tolerably  uniform  size,  about  an  inch  wide,  one-third 
of  an  inch  thick,  and  seven  inches  long,  but  are  very  rough.  They  are  next 
passed  through  a  planing-machine,  which  smooths  them,  and  a  rounding-ma- 
•chine,  which  cuts  off  the  corners,  and  then  are  sawed  to  the  proper  length.  Each 
pencil  is  afterward  sharpened  separately  on  a  grindstone.  The  waste  is  very 
great,  as  not  more  than  one-hnndredth  of  the  original  stone  appears  in  the  form 
of  pencils.  This  refuse  is  ground  three  grades  finer  than  superfine  flour,  and  used 
to  mix  with  paper  pulp  to  give  it  body,  as  it  is  termed,  and  a  satin  finish. 

t  Talc  is  found  as  a  compact  rock  in  North  Carolina.  It  is  largely  used  as  a 
black-board  crayon. 


262  QUESTIONS. 

62.  Characteristic  features  of  the  landscape  in  a  trappean  region  ? 
Proof  of  the  igneous  origin  of  basalt  ? 

64.  Curious  relation  between  the  civil  and  geologic  history  of 
trappean  countries  ?     Name  the  three  varieties  of  volcanic  rocks. 
Describe  trachyte  ?     Noted  peak  of  trachyte  ?*     What  is  lava  ? 

65.  Scoria?     Its  uses?    Pumice?     Its  uses?    What  are  the  char- 
acteristic features  of  the  landscape  in  a  volcanic  region  ?     Define 
metamorphic  rocks. 

66.  What  effect  would  melted  lava  have  on  sedimentary  rocks  ? 
Illustrate.     Cause  of  fossils  in  certain  kinds  of  marble  ?    Imperfec- 
tions in  marble  ?    Composition  of  granite  ?     How  may  its  constitu- 
ents be  distinguished  ? 

67.  What  is  graphic  granite  ?     Is  the  structure  of  granite  uni- 
form ?     Its  value  for  various  uses  ?     Its   location   in  the  earth's 
crust  ?     Process  of  quarrying  granite  ? 

68-9.  Estimate  of  granite  by  the  ancients  ?  Is  granite  a  primi- 
tive rock  ?  Has  the  original  crust  of  the  earth  been  preserved  un- 
changed ?  State  what  changes  it  has  probably  undergone.  Could 
granite  crystallize  directly  out  from  lava  ?  State  the  theory  of  the 
formation  of  granite.  If  granite  be  not  an  igneous  rock,  how  do 
you  explain  the  fact  that  it  has  been  thrown  up  in  a  melted  state  ? 
What  are  the  various  aspects  which  granite  assumes  in  a  land- 
scape ? 

71.  What  is  the  general  appearance  of  a  granitic  region  ?     What 
effect  has  the  purity  and  sublimity  of  nature  upon  the  inhabitants? 
Difference  between  granite  and  gneiss  ? 

72.  Origin  of  gneiss?     Its  use?     Appearance  of  gneiss  hills? 

73.  What  is  mica  schist?     Character  of  a  mica  schist  landscape? 
What  noted  scenery  is  of  this  description  ?    What  is  syenite  ?    Why 
so  called  ?   Was  this  name  correctly  applied  ?    Is  "  Quincy  granite  " 
a  true  granite  ? 


*  Chimborazo  is  a  trachytic  dome,  which  is  a  characteristic  feature  of  the  moun- 
tain scenery  among  the  Andes,  as  sharp  granitic  pinnacles  are  of  the  Alps.  (See 
page  69.)  It  is  a  majestic  pile  of  snow,  white  as  if  cut  out  of  spotless  marble. 
Yet  it  once  gleamed  with  volcanic  fires.  Its  ancient  name,  Chimpurazu,  meant 
mountain  of  snow.  It  is  a  little  singular  to  notice  how  many  lofty  peaks  in  the 
world  are  thus  named— Himalaya,  Mont  Blanc,  Hcemus,  Sierra  Nevada,  Ben 
Nevis,  Snowdon,  Lebanon,  White  Mountains,  Chimborazo,  and  Illimani.— Or- 
ion's ^A  ndes  and  the  A  mazon" 


Q  U  E  STI  ONS. 

74.  What  is  quartzite  ?     Repeat  the  effects  of  metamorphic  action 
on  limestone.     Cause  of  colored  veins  in  marble  ?     How  are  rocks 
classified  according  to  their  structure  ? 

75.  Which  class  is  the  more  abundant  on  the   exterior  of  the 
earth's  crust  ?     On  the  interior  ?     Which  is  of  the  greater  value  in 
geologic  study  ?     Does  the  crust  remain  of  the  same  thickness  ? 
How  are  igneous  rocks  worked  over  into  stratified  rocks  ?     How 
are  stratified  rocks  generally  deposited  ? 

76.  Show  how  igneous  action  has  disturbed  this  uniform  arrange- 
ment.    Value  of  this  disturbance  in  geologic  study  ?     Define  out- 
cropping. 

77.  Define  stratum,  formation,  group,  and  lamina.     Name  and 
define  the- various  terms  used  to  indicate  the  position  of  strata. 

78.  When   are  strata  conformable?     What  is  diverse  stratifica- 
tion ?     Distinguish  between  lamination  and   stratification.      State 
the  circumstances  under  which  different  kinds  of  lamination  are 
produced. 

79.  Define  a  fault.     A  jointed  structure.     Illustrate. 

80.  Value  to  the  quarrymen  ?     Cause  of  these  seams?    What  are 
folds?     How  produced  ? 

81.  What  is  a  decapitated  fold  ?     Effect  in  apparently  displacing 
strata  ?     Illustrate. 

82.  What  is  a  concretion  ?     The  nucleus  ?     A  septarium  ? 

83.  A  claystone  ?     A  geode  ?     A  beetle-stone  ? 

84.  A  slate  structure  ?     How  produced  ?     How  do  the  unstrati- 
fied  rocks  occur  ? 

85.  What  is  a  vein  ?     A  dike  ?     Meaning  of  the  term  ? 

86.  State  Hugh  Miller's  beautiful  comparison. 

87.  How  can  the  relative  age  of  veins  or  dikes  be  estimated? 
What  proof  is  there  that  some  veins  have  been  filled  from  below 
With  melted  matter  ? 

88.  Describe  the  various  ways  in  which  Nature  mends  her  rock- 
rents. 

90.  How  have  metallic  veins  been  formed  ?    What  is  a  lode  ? 


Q  UE  S  TI 0  N S. 


THIRD       PART. 

HISTORICAL  GEOLOGY. — Define  historical  geology.  Name  some 
of  the  difficulties  the  geologist  finds  in  reading  this  history.  Value 
of  fossils  ?  Why  does  the  identification  of  a  fossil  identify  a  forma- 
tion ?  Are  the  geologic  ages  clearly  separated  ?  What  terms  are 
used  to  designate  the  lesser  divisions  ? 

96.  Name  and  define  the  four  different  Times  of  geologic  his- 
tory. On  what  are  these  divisions  based  ? 

THE  Azoic  TIME. — Location  of  the  Azoic  rocks  ?  Is  America 
the  "  new  world  ?  "  * 

100.  Name  the  kinds  of  Azoic  rocks.     How  formed  ?    What  ores 
do  they  contain  ?     Was  there  ever  a  true  Azoic  time  ?     Is  it  defi- 
nitely fixed  ?     State  the  historyoftheEozoon  Canadense.    What  are 
rhizopods  ?     (See  further  account  on  page  188.)     What  other  name 
do  these  fossils  have  ? 

101.  Is  the  Eozoon  accepted  universally  as  a  fossil  ?    What  effect 
would  its  admission  have  ?     How  are  the  relative  ages  of  moun- 
tains indicated  ?     The  oldest  mountains  in  the  world  ? 

102.  Describe  the  effect  of  the  metamorphic  action  on  the  Azoic 
rocks. 

103.  Divisions  of  the  Azoic  rocks  in  Canada.     State  the  proba- 
bility that  life  existed  at  that  early  day,  and  that  vegetable  life  had 
the  precedence. 

104.  Show  how  the  frame-work  of  the  continent  was  developed  in 
the  Azoic  Time.     The  parallel  which  exists  between  the  Mosaic 
and  geologic  accounts. 


*  The  oldest  land  in  South  America  is  in  Guiana.  Its  granite  peak  rose  above 
the  ocean  an  island  where  now  expands  a  continent.  Its  Azoic  rocks,  together 
with  those  of  Brazil,  which  afterward  appeared  as  a  cluster  of  islands,  were  for 
ages  the  only  dry  land. south  of  the  Canada  Hills.  While  the  Creator  was  build- 
ing up  a  continent  at  the  north,  the  south  seems  to  have  been  left  for  a  later  age 
to  develop.  Carboniferous  vegetation  mantled  the  coal  regions  with  a  gorgeous 
flora,  monstrous  saurians  paddled  the  waters  of  the  upper  Atlantic  coast,  and 
huge  dinotheria  wallowed  in  the  mire  where  now  stand  the  palaces  of  Paris, 
London,  and  Vienna,  but  as  yet  only  the  broad  table-land  of  Guiana  and  Brazil 
appeared  above  the  waste  of  the  Palaeozoic  Sea.— Sec  Orion's  "Andes  ^and 
tAt  Amazon" 


q  v  i:  ,s  T  i  o  x  ,s .  ;.v;/7 

[If  the  chapter  on  Natural  History  be  learned,  the  questions  will 
readily  suggest  themselves.] 

THE  PAL/EOZOIC  TIME. — Name  the  ages  of  the  Palaeozoic  Time. 

THE  SILURIAN  AGE. — Why  is  the  age  so  called  ?  Name  the 
periods  of  the  Silurian  Age.  Why  is  the  New  York  survey  taken 
as  the  basis  of  the  Silurian  and  Devonian  Ages.-" 

no.  State  the  method  by  which  the  continent  grew.  The  gen- 
eral characteristics  of  the  Silurian  Age. 

in.  Location  of  the  Potsdam  rocks  ?     Kinds  of  rocks  ? 

112.  Describe  the  lingula.     The  trilobitc. 

114.  The  atmosphere  of  the  Potsdam   Period. f     The  early  Silu- 
rian beach.     What  sub-kingdoms  of  animals  were   represented  ? 
Was  there  any  vegetation  ?     Any  distinction  of  zones  ? 

115.  Reasons  for  this  uniformity?     Show  how  changes  in  the  sea 
produced  corresponding  changes  in  the  life  and  the  rock.     What 
geologic  events  occurred  in  the  Lake  Superior  region  ? 


*  This  system  has  been  established  by  the  genius  and  the  indefatigible  perse- 
verance of  James  Hall,  LL.D.,  State  Geologist.  To  his  labor  the  world  is  in- 
debted for  a  palaeontological  work  on  the  rocks  of  New  York,  the  compeer  of 
Murchison's  on  the  Silurian  of  Europe. 

t  Nature  does  nothing  by  halves.  She  does  not  stop  at  fractions  of  enter- 
prises. She  never  forsakes  a  part  until  it  becomes  a  whole.  Her  works  are  often 
a  process ;  often  is  the  process  long,  but  provision  is  always  made  for  finishing 
up  in  a  congruous  manner  whatever  she  has  undertaken.  Many  human  works 
are  finally  forsaken  at  various  stages  of  incompleteness— machines,  edifices, 
books.  Nature  is  no  Michael  Angelo,  leaving  piles  of  unfinished  productions. 
All  her  parts  bid  us  look  for  wholes.  Did  you  ever  find  a  fraction  whose  integer 
is  not  come  or  coming  ?  When  you  see  the  crescent  moon,  be  sure  that  the  rest 
of  the  sphere  is  by  its  side,  though  for  the  present  unillumined.  Look  more 
closely  ;  perhaps  you  may  discern  the  old  moon  in  the  new  moon's  arms.  Look 
more  closely ;  perhaps  you  may  discover  over  against  yonder  organic  need  in 
Nature  a  full  supply  for  that  need  which  Nature  has  provided.  But  whether  you 
discover  it  or  not,  make  sure  that  the  supply  exists.  Nature  does  not  waste  her- 
self. She  has  no  fondness  for  throwing  herself  away  either  wholly  or  in  parts. 
If  you  find  one  of  her  reservoirs,  make  sure  that  there  is  something  to  put  in 
it,  and  as  much  as  it  will  hold.  If  you  find  one  of  her  tools,  be  certain  that  it 
has  something  to  do,  and  as  much  as  it  can  do  well.  A  good  and  careful  pro- 
vider is  she,  and  never  to  be  reckoned  as  an  infidel  who  does  not  care  for  his 
own  !  Cuvier  finds  a  bone,  and  he.  at  once  reconstructs  the  whole  animal  to 
which  it  belongs.  How  ?  On  the  observed  fact  that  whatever  is  needed  to  com- 
plement a  full  mechanism  in  Nature  exists  or  has  existed — that  wherever  shines  a 
Castor  of  a  demand,  over  against  it  shines  also  the  twin  Pollux  of  a  supply. — 
Pater  Mundi,pp.  233-5. 

la 


Q  UE  S  TI  0  NS. 

116.  Draw  the  parallel  between   the   Mosaic  and  geologic  ac. 
counts. 

117.  Location   of  Trenton   rocks  ?     Principal  kinds  of  rocks  ? 
Name  the  epochs. 

118.  Scenery  of  the  Galena  limestone.     Fossils  of  the  Chazy. 

1 19.  Characteristic  fossils  of  Bird's  Eye  and  Black  River  lime- 
stones.    Describe  the  orthoceratite. 

120.  What  is  the  siphuncle  ?     Were  species  constant  ?     Did  ani- 
mals die  as  now  ? 

122.  What  sub-kingdoms  of  animals  existed?    Any  terrestrial 
plants  ?   What  mountains  were  elevated  at  the  close  of  the  period  ? 
How  is  this  known  ?     Location  of  Hudson  rocks  ?     By  what  other 
name  is  the  formation  known  ?     Kinds  of  rock  ?     Does  it  contain 
any  coal  ? 

123.  Describe  the  graptolite.     Geography  of  the  Hudson  Period. 

124.  Location  of  Niagara  rocks  ?     Why  so  called  ?     Name  the 
epochs. 

125.  What  is  Niagara  limestone  called  in  Chicago  ?     Minerals 
at  Lockport  ?    Appearance  at  the  west  ?    What  abundant  and  inter- 
esting fossil  ?     Describe  the  fucoids. 

126.  The  crinoids  ?   What  common  name  has  the  crinoid  ?  What 
is  crinoidal  (encrinital)  limestone  ? 

127.  Condition  of  the  Appalachian  region  during  this  period  ? 
Location  of  Salina  rocks  ? 

129.  Kinds  of  rock  ?   Why  is  it  so  destitute  of  fossils  ?     Explain 
the  Salt  Springs.     The  gypsum  beds. 

130.  Location  of  the  Lower  Helderberg  rocks?     Kind  of  rock? 
Name  of  the  lower  beds  ?     What  is  said  of  the  abundance  of  fos- 
sils ?     Describe  the  eurypterus. 

.  131.  The  tentaculites.   Geography  of  this  period. 

132.  The  climate.  What  animals  took  the  lead  ?  What  classes 
were  yet  wanting  to  complete  the  scheme  of  life  ?  Illustrate  the 
uniformity  of  Nature  in  all  ages.  The  changes  which  took  place  in 
the  life  at  various  times. 

THE  DEVONIAN  AGE. — Why  so  called?  What  name  has  it  in 
England?  Is  it  a  red  sandstone  in  America ?  Name  its  periods. 
Describe  the  general  characteristics  of  the  age.  What  is  the  promi- 
nent feature  ? 


Q  UE  ST  I  0  NS. 

135.  What  is  a  ganoid  ?  Name  and  describe  the  five  principal 
kinds  of  fish — the  coccosteus,  the  pterichthys,  the  cephalaspis,  the 
holoptychius,  and  the'osteolepis. 

137.  Illustrate  their  singular  union  of  reptilian  and  fishy  traits. 
What  is  a  comprehensive  type  ?  A  prophetic  and  a  retrospective 
one? 

139.  Location  of  Oriskany  rocks  ?     Kind  of  rock  ? 

140.  Its  characteristic  fossils  ?    Condition  of  the  sea  along  the  old 
Appalachian  beach  ? 

141.  Location   of  the    Upper   Helderberg   rocks  ?     What   other 
name  is  applied  to  them  ?   Why  ?     Name  the  epochs.    Which  stone 
is  most  valuable  for  building  purposes  ?    What  is  "  chert "  ? 

142.  Characteristic  fossil  ?     Location  of  the  Hamilton  rocks  ? 

143.  Name  the  epochs  and  describe  the  different  rocks.     Physi- 
cal features  of  districts  underlaid  by  Hamilton  rocks. 

144.  By  what  name   is   the  Genesee  slate  known  at  the  west  ? 
Describe  the  goniatite.     The  cup  coral. 

146.  For  what  is  the  phacops  bufo  distinguished  ?  When  did 
terrestrial  plants  first  appear  ?  Location  of  Chemung  rocks  ? 
Name  the  epochs.  Under  what  circumstances  were  the  Chemung 
rocks  deposited?  What  are  its  prominent  fossils?  Its  geo- 
graphy ? 

.  THE  CARBONIFEROUS  AGE. — Why  so  called  ?  Name  the  periods. 
The  general  characteristics  of  the  age  ?  Its  geography  ?  The  con- 
ditions favorable  to  the  growth  of  vegetation  ?  The  formation  of 
.coal  ?  The  frequent  oscillations  of  the  land  ? 

152.  Location  of  the  Sub-Carboniferous  rocks?  Kinds  of  rock  ? 
Curious  appearance  which  they  sometimes  present?*  Prominent 
fossils  ?  Describe  the  "  sink  holes  "  found  in  this  formation.  The 
caves. 

154.  Peculiarity  of  the  fish  found  in  the  Mammoth  Cave  ?    What 
animals  appeared,  as  it  were,  before  their  time  ?     Location  of  Car- 
boniferous rocks  ?     Name  the  six  great  coal-fields  of  the  United 
States.     What  are  the  False  Coal  Measures  ? 

155.  Kinds  of  rock  ?      State   some   facts   with   regard   to   coal 


*  These  remains  are  popularly  styled  rock-cities.    Several  are  found  in  the 
south-western  part  of  New  York. 


268  QUESTIONS. 

seams.     The  effect  of  pyrites.     What  are  the  characteristic  fos- 
sils ? 

156.  Describe   the  Carboniferous  vegetation.     The  ferns.     The 
calamites. 

157.  The   sigillarise.     The  lepidodendra.     The  stigmarise.     The 
conifers.     Reptilian  remains.     Insects.     Fishes. 

162.  Location  of  Permian  Period.     Why  so  called  ?     Kinds  of 
rock  ?    Curious  kind  of  limestone  found  near  Manhattan,  Kansas  ? 

163.  Describe  the  character  of  the  Permian  fossils.     The  Appa- 
lachian revolution. 

164-5.  Illustration  of  the  subsequent  denudation  seen  at  Cham- 
bersburg,  Penn.  The  metamorphic  action.  Beneficent  effects  of 
this  upheaval  and  metamorphism.  The  progress  of  life. 

THE  MESOZOIC  TIME. — Name  the  periods  of  the  Mesozoic  Time. 
The  general  characteristics  of  the  Age  of  Reptiles. 

167.  Grand   characteristic  ?      The  geography  ?      Origin   of  the 
terms  Triassic  and  Jurassic  ? 

168.  What  name  is  sometimes  given  to  the  Triassic  rocks  in 
Europe?     What  are  the  European  divisions  of  the  Jurassic  rocks? 

169.  Location  of  the  Triassic  and  Jurassic  rocks  in  the  United 
States  ?     Describe  the  formation  of  the  rocks.     Kinds  of  rock.     Is 
coal  found  ? 

170.  What  change  took  place  in  the  character  of  the  vegetation  ? 
Describe  «he  cycad.     Show  that  it  is  a  comprehensive  type.     What 
classes  now  make  their  appearance  ?     Had  birds  or  mammals  been 
known   before?     Describe   the  various   kinds  of   fossils — insects, 
fishes,  oysters,  crinoids,  etc. 

171.  In  what  families  did  the  class  of  cephalopods  culminate? 
Describe  the  ammonite. 

172.  How  did  the  ammonite  sink?     Describe  the  belemnite. 

173.  Common  names?    What   is   said  of  the   cuttle-fish?    The 
fchthyosaur  ? 

174.  Coprolites?     Beetle-stones? 

177.  Tell  the  story  of  Mary  Anning. 

178.  Describe  the  plesiosaur.    The  pterodactyle.     How  were  the 
fins  of  the  Devonian  fishes  a  prophecy  of  man  ? 


QUESTIONS.  269 

181.  Describe  the  dinosaurs.     What  are  the  names  of  the  princi- 
pal of  these  land  reptiles  ? 

182.  Describe  the  megalosaur.     The  iguanodon.     The  restora- 
tion of  the  latter  animal.     What  striking  illustration  of  the  mutual 
adaptation  of  the  various. parts  of  the  animal  occurred  in  the  restora- 
tion of  the  megalosaur?*   What'naturalist  discovered  this  principle 
in  comparative  anatomy  (p.  203)  ? 

183.  Describe  the  labyrinthodon.    The  ramphorhyncus. 

184-5.  The  "bird-tracks"  of  the  Connecticut  valley.  What  is 
said  of  the  animal  by  which  they  were  made?  What  was  the  cli" 
mate  at  that  time  ? 

1 86.  Describe  the  Triassic  salt-beds  of  Europe.  The  Triassic 
gold-bearing  rocks  of  California.  What  was  the  origin  of  the  gold 
placers? 


*  The  following  is  an  extract  from  a  letter  on  this  subject  received  from  Dr. 
Hawkins  too  late  for  insertion  in  its  proper  place,  but  which  is  too  valuable  to  be 
omitted : 

u  In  the  first  instance,  I  was  much  affected  toward  it  by  reading  that  admirable 
work,  The  Bridgewater  Treatise  on  Geology,  written  by  the  Rev.  Dr.  Buckland, 
in  which  he  describes  the  teeth  of  that  gigantic  saurian,  and  so  graphically  com- 
pares them  to  the  combination  of  knife,  saw  and  scimeter,  which,  with  the  fossil 
fragment  of  the  jaw  in  my  hand,  could  not  fail  to  impress  me  with  a  precise  idea 
of  the  manner  in  which  this  creature  devoured  its  prey.  He  did  not  snap  and 
swallow  like  an  alligator,  but  did,  with  tooth  and  claw,  cut  off  and  tear  the  flesh 
of  his  victim,  like  the  lion  or  tiger.  The  fragment  of  the  jaw  also  gave  a  definite 
conception  of  the  dimensions  of  the  head,  and  explained  the  necessity  for  the 
animal  to  have  an  active  power  over  the  formidable  weapons  with  which  he  con- 
quered and  devoured  his  prey.  To  do  this  successfully,  it  was  necessary  for  the 
strong  tendon  attached  to  the  back  of  the  head  to  be  also  firmly  anchored  at  its 
other  extremity  to  the  long  spines  of  the  nerve-arches  at  the  junction  of  the  neck 
and  back,  as  in  the  horse,  stag,  elephant,  tiger,  and  all  animals  having  an  active, 
use  for  a  large  and  heavy  head.  This  theoretical  reasoning  and  conviction  1  em- 
bodied in  a  preliminary  sketch  with  the  elevated  ridge  on  the  fore  part  of  tho 
back,  to  submit  to  the  learned  savans  whom  I  had  the  privilege  of  consulting  a\ 
that  time,  and  by  whom  it  was  condemned  as  exceptional  in  the  case  of  reptiles. 
My  convictions,  however,  were  too  strong  to  allow  me  to  yield  to  their  decision. 
I  therefore  commenced  this  gigantic  model  in  the  spring  of  the  year  1854,  an<f 
completed  it  the  xoth  June  of  the  same  year. 

The  supposititious  hump-like  ridge  continued  to  excite  various  criticisms  as  to 
its  probability.  At  the  end  of  the  same  year  I  had  'the  pleasure  of  receiving  q 
visit  from  Prof.  Richard  Owen  to  congratulate  me  on  the  discovery  in  th* 
Wealden  sandstone,  Sussex,  of  the  bones  which  justified  the  exceptional  form 
which  I  had  predicated." 


270  QUESTIONS. 

187.  Describe  the  disturbances  that  marked  the  close  of  the 
Jurassic  Period.  What  noted  scenery  is  of  this  era?  Location  ot 
the  cretaceous  rocks  ?  Kinds  of  rock  ? 

188-9.  Describe  the  "  green-sand  "  of  New  Jersey.  What  is  said 
of  the  cretaceous  coal-beds?  Appearance  of  chalk  under  the  mi- 
croscope? What  is  said  of  rhizopods?  Curious  story  told  of 
Ehrenberg  ? 

190.  What  is  said  of  the  deep-sea  dredgings  ?  Are  we  not  now 
living,  in  a  certain  sense,  in  the  Cretaceous  Period?  Are  the 
American  fossils  of  this  period  different  from  the  English?  Why? 

191-4.  Describe  the  cimoliasaur.  The  mosasaur.  The  snapping- 
turtles.  The  crocodiles.  The  dinosaurs.  The  hadrosaur.  The 
laelaps. 

Describe  the  great  disturbances  which  took  place  at  the  close  of 
the  Mesozoic  Age.  Cause. 

CENOZOIC  TIME. — Name  its  periods.    Its  general  characteristics. 

196.  Its  geography.     The  epochs  of  the  Tertiary  Period.     Origin 
of  the  term  "  Tertiary."     Geological  condition  of  Europe.     Euro- 
pean divisions  of  the  Tertiary. 

197.  Location  of  the  Tertiary  rocks.     How  do  we  determine  the 
way  in  which  its  deposits  were  formed  ?     Describe  the  "  pine  bar- 
rens."    Extent  of  Tertiary  rocks  on  the  Pacific  coast. 

198.  Kinds  of  rock.      What  is  nummulitic  limestone  ?     Where 
found  ?     The  Tertiary  coal-beds  ?     Is  coal  found  below  the  Carbon- 
iferous rocks?     Above?     What  is  said  of  the  abundant  vegetation? 

199-202.  What  peculiar  kinds  of  plants,  not  belonging  to  those 
regions  at  present,  are  found  fossil  ?  What  do  they  teach  ?  How 
many  species  of  Tertiary  shells?  Theirs  appearance ?  Name  the 
various  kinds  of  animal  remains.  What  is  said  of  the  insects 
found?  *  Describe  the  zeuglodon. 


*  The  story  that  these  beds  tell  seems  to  be  this :  A  large  fresh-water  or  brack- 
ish lake  existed,  covering  a  considerable  portion  of  western  Colorado  and  eastern 
Utah.  Streams  carried  down  fine  sediment  and  free  petroleum,  from  numerous 
springs  in  the  surrounding  country,  for  ages ;  the  petroleum  increased  in  flow 
until  the  sediment  of  the  lake  became  thoroughly  charged  with  it,  and  the  can- 
nelite  was  the  result.  A  change  in  the  level  of  the  country  and  the  course  of  the 
streams  is  indicated  by  the  overlying  sandstones  and  conglomerates,  nearly  desti- 
tute of  petroleum,  and  at  least  one  thousand  feet  in  thickness.  During  the  time 
that  this  immense  amount  of  sediment  was  being  deposited,  * /illows,  maples, 


QUESTIONS. 

203.  Give  an  account  of  the  discoveries  made  by  Cuvier  in  the 
Paris  basin. 

204.  What  was  probably  the  character  of  this  region  at  that  time? 
Describe  the  paleotherium.    How  do  we  know  that  flowers  existed 
in  the  Tertiary  Period  ? 

205.  What  is  said  of  the  Bad  Lands?     Where  are  they?     What 
fossils   do   they  contain?     What   animals,  since  domesticated  by 
man,  inhabited  the  shores  of  that  Tertiary  sea  ?*      Describe   the 
titanotherium. 

206.  What  was  the  probable  origin  of  this  region  ?     Were  there 
probably  more  than  one  of  those  great  fresh-water  lakes  in  the 
Tertiary  Period  ? 

207.  Name  the  epochs  of  the  Post-Tertiary.     Condition  of  the 
continent  at  this  time.     What  change  ensues? 

208.  What  is  the  Drift  ?     Its  extent  ?    What  is  said  of  bowlders — 
their  size  and  appearance  ? 

209.  From  what  direction  did, they  come?     Illustrate. 

210.  What  are.  lost  rocks?    Why  are  bowlders  more  abundant  at 
the  east  than  at  the  west  ?     What  are  glacial  striae  ?     Describe  their 
appearance.     What  is  their  general  direction  ?     On  which  side  of 
mountains  are  they  found  ? 

212.  How  high   do   they   extend?     Describe   the   formation   of 
glaciers  in  Alpine  valleys. 

215.  Define  the  different  kinds  of  moraines.     Tell  how  blocks 
are  conveyed  to  a  distance.     How  striae  are  cut. 


oaks,  and  many  strange  trees  grew  on  the  land,  palseotheres  and  turtles  swam  in 
the  waters,  and  clouds  of  insects  sported  over  its  surface.  The  bitumen  seems  to 
have  flowed  from  the  shales  as  petroleum  after  their  upheaval,  and  to  have  hard- 
ened in  time  into  its  present  form.  The  character  of  the  ancient  Vegetation  is 
shown  by  the  fossil  wood  found  in  great  abundance.—  Proc.  Boston  Soc.  of  Nat* 
History,  1866. 

*  "  Tt  is  a  marvelous  fact  in  the  history  of  mammalia  that  in  South  America  a 
native  horse  should  have  lived  and  disappeared,  to  be  succeeded  in  after  years  by 
countless  herds  descended  from  the  few  introduced  by  the  Spanish  colonists." 
(Darwin.)  These  domestic  animals,  which  were  then  native  in  America,  were 
not  of  exactly  the  same  species  as  those  now  used  by  man.  The  fossil  remains  of 
a  horse  have  been  found  at  the  west,  which,  when  alive,  could  not  have  been 
three  feet  high.  Horses  had  entirely  disappeared  from  the  continent  when  the 
Spaniards  landed,  and  the  Indians  supposed  man  and  beast  to  be  one  animal. 


272  QUESTIONS. 

216.  Name  the  evidences  of  former  glaciers.  Describe  the  great 
glacier  on  the  coast  of  Greenland. 

217-18.  How  are  icebergs  formed  ?  What  effect  do  they  have  in 
the  transportation  of  rock  and  formation  of  striae  ?  Describe  the 
origin  of  the  glaciers  of  the  Drift  epoch.  Cause  of  the  cold.* 
The  effects. 

219.  What  change  occurred  in  the  Champlain  Epoch?  Its  effect? 
What  proof  have  we  that  river-channels  were  filled  by  these 
glaciers  ? 

220-21.  Effect  of  the  glacier-streams  ?  How  does  the  coarseness 
of  the  Drift  vary?  Effects  of  this  change?  Describe  the  continen- 
tal elevation  which  took  place  at  the  beginning  of  the  Terrace 
Epoch.  Its  effect?  Was  the  elevation  uniform  and  steady? 

222.  What  are  the  proofs  of  these  oscillations  ? 

223-4.  How  were  terraces  formed  ?  Which  were  made  in  the 
Champlain  Epoch  ?  The  Terrace?  What  are  ancient  sea-beaches? 
How  are  they  known  ?  How  high  are  they  found  ? 

225-6.  Localities  of  Post-Tertiary  fossils?  Do  they  resemble 
modern  species?  What  animals  led  the  life  of  the  period?  Name 
the  principal  quadrupeds,  Describe  the  mammoth. 


*  There  is  a  growing  conviction  that  the  cause  of  this  glacial  cold  must  be 
sought  among  astronomical  phenomena.  It  has  been  suggested,  i.  That  we  are 
now  moving  through  a  comparatively  starless,  and  hence  cheerless,  region  -of 
space  ;  and  that  as  the  earth  passes  from  densely  to  thinly-clustered  portions,  and 
•vice  versa,  the  heat  received  and  consequent  temperature  must  vary  ;  2.  That 
the  axis  of  the  earth  may  not  have  always  pointed  in  the  same  direction  or  at  the 
same  angle  as  now,  and  that  any  variation  would  have  produced  a  change  of  cli- 
mate ;  3.  That  during  the  Great  Year  of  the  astronomers,  about  21,000  common 
years,  each  hemisphere  has  two  seasons  (see  Astronomy,  page  121,  et  sey.).  Dur- 
ing half  of  this  time  the  northern  hemisphere  has  its  summer  in  aphelion,  and 
winter  in  perihelion  ;  while  in  the  other  half  this  is  reversed.  When  the  Great 
Winter  prevails  at  the  north  pole,  there  is  an  accumulation  of  ice  and  snow. 
This  changes  the  center  of  gravity  of  the  earth.  The  water  will  flow  thither  to 
adjust  the  equilibrium,  and  thus  overflow  a  part  of  the  northern  hemisphere. 
These  Great  Summers  and  Winters,  with  their  accumulations  of  snow  and  ice, 
and  consequent  submergence  of  the  land,  have  occurred,  it  is  thought,  alternately 
at  either  pole  at  intervals  of  about  10,500  years  through  all  the  past.  In  the  year 
1250  (see  Astronomy,  p.  129)  the  Great  Winter  terminated  at  the  south  pole, 
where  for  12,500  years  these  accumulations  had  been  gathering.  In  the  same 
year  the  Great  Northern  Summer  culminated.  The  hemisphere  which  has  its 
winter  in  aphelion  is  not  only  further  from  the  sun,  but  has  a  winter  of  eight  days 


Q  UEST10XX.  273 

227.  The  locality  of  fossil  ivory  in  Siberia?   What  curious  legend 
have  the  Tartars?    Describe  the  discovery  of  a  mammoth  preserved 
in  ice. 

228.  The   mastodon.      How    can   mastodon  remains  be   distin- 
guished from  those  of  the  elephant  ? 

229.  What  was  the  mastodon's  food ?     How  is  this  known?     De« 
scribe  the  megatherium.     What  was  its  food?     Uses  of  its  tail? 
Was  its  structure  adapted  to  its  life  ? 

230-4,  Describe  the  glyptodon.  The  Irish  elk.  The  cave-bear. 
Why  so  named  ?  The  hyena.  Discovery  of  the  Kirkdale  cave. 

236.  What  is  said  by  Whitney  of  the  Glacial  Epoch  in  California  ? 
Is  any  Drift  found  in  Oregon? 

237.  Origin  of  canons.    What  is  the  Loess  of  the  Nile  ?     The 
Rhine?     The  Mississippi  valley? 

238.  Its  location  and  appearance?     Its  fossils?    What  are  sand- 
dunes  ?     Where  found  ?     How  formed  ? 

THE  ERA  OF  MIND. — Does  Geology  tell  when  man  appeared? 
Where  are  his  remains  found  ? 

244-7.  Name  the  classifications  of  these  primeval  remains. 
What  do  tfiese  terms  indicate?  Were  these  ages  coeval?  De- 
scribe the  man  of  the  Stone  Age  in  the  first  epoch.  The  second 
epoch.  The  third  epoch. 

248-9.  Influence  of  the  metals  in  advancing  civilization?  What 
metals  were  first  used  ? 

250.  Describe  man's  progress  in  the  Bronze  epoch.  The  Iron 
epoch. 

longer  duration  (Astronomy,  p.  118).  M.  Adhemar  has  worked  out  this  theory 
very  fully.  He  claims,  however,  that  owing  to  the  movement  in  the  Earth's 
orbit  (Astronomy,  p.  128),  the  Great  Year  is  only  21,000  years  long  ;  each  hemi- 
sphere having  a  summer  of  10,500  years  and  a  winter  of  equal  length.  The  Great 
Summer  of  the  northern  hemisphere  culminated,  according  to  his  calculations,  1248 
B.C.  Since  that  date  our  Great  Winter  has  been  in  progress.  Our  pole,  in  its 
turn,  goes  on  getting  cooler  continually ;  ice  is  being  heaped  upon  snow,  and 
snow  upon  ice,  and  in  seven  thousand  three  hundred  and  eighty-eight  years  the 
center  of  gravity  of  the  earth  will  return  to  its  normal  position,  which  is  the 
geometrical  center  of  the  spheroid.  Following  the  immutable  laws  of  central 
attraction,  the  southern  waters  accruing  from  the  melted  ice  and  snow  of  the 
south  pole  will  return  to  invade  and  overwhelm  once  more  the  continents  of  the 
northern  hemisphere,  giving  rise  to  new  continents,  in  all  probability,  hi  the 
southern  hemisphere. 


A  TRIASSIC  FISH. 


i.  Eurinotus  ceratocephalus. 


, 

x--**  f • 


ACALZPH,  Ak'-a-lef. 
AGATE,  Ag'-ate. 
ALBITE,  Al'-mte, 
ALUMINA,  A-lu'-me-na. 
ALUMINIUM,  Al-tt-mm'-e-um. 
AMETHYST,  Am'-e-thyst. 
AMYGDALOID,  A-mig'-ddrloid. 
ANOPLOTHERIUM,  An-o-plo-the'-re-um. 
AKGILLACEOUS,  Ar-fd-a'-shus. 
ASBESTOS,  As-bes'-tus. 
ASTEROPHYLLITE,  As-ter-off'-e-ltte. 
AUGITE,  Aw'-jlte. 

BASALT,  Ba-sawW. 
BELEMNITE,  Be-lem'-rilte. 
BRACHIOPOD,  Brack' -e-o-pod. 
BBYOZOAN,  Bri-o-zo'-an. 

CALAMITE,  KaP-d,-mite. 
CEPHALASPIS,  Sef-a-las'-pis. 
CEPHALOPOD,  Sef'-dl-o-pod. 
CHALCEDONY,  Kal-sSd'-o-ny. 
CHKYSOPKASE,  Krys'-o-prase. 
COCCOSTEUS,  Koe-cos'-te-us. 
CONCHOIDAL,  Kon-koi'-dal. 
CONGLOMERATE,  Kon-gtomf-e-rate. 
CONIFER,  Kd'-nl-fer. 
CORAL,  Kw'-al. 
CRETACEOUS,  Kre-ta'-shus. 
CRINOID,  Krl-noid. 
CRUSTACEAN,  Krus-ta'-she-an. 
CYCAD,  Sy'-kad. 

DEVONIAN,  De-v5'-ne-an. 
DINOSAUR,  Di'-nosawr. 
DINOTHERIUM,  Di'-no-the'-re-wn. 
DODECAHEDRON,  Do-dec-drke'-dron. 


DOLOMITE,  JDol'-o^nite  ;  (Dolomien,  a 

French  geologist.) 
DOLERITE^  Dol'-e-rite. 

ECHINODERM,  JS-kin'-o-derm. 
ECHINOIDS,  Ek-i-noids. 
ENCRINITE,  En'-kre-nite. 
ENDOGEN,  En'-do-jen. 
EUBYPTERUS,  Eu-ryp'-te-rus. 
EOCENE,  E'-d-seen. 
EQUISETACE^E,  E-que-se-t&'-she-e. 
EQUISETUM,  Eq-ue-se'-tum. 
EXOGEN,  Ex'-o-jen. 
EozoO*,  E-oztf-an. 

FAUNA,  Fawn'-a. 
FELDSPAR,  Feld'-spar. 
FORAMENITERA, 


GANOID,  Ga'-noid. 
GASTEROPOD,  Gas'-ter-o-pod. 
GEODE,  Jef-dde. 
GLACIER,  Glci-seer. 
GNEISS,  Nice. 
GONIATITE,  Gd'-m-a-tite. 
GRANITE,  Grari'-U. 
GRAPTOLITE,  Grap'-to-Hte. 
GYPSUM,  Jlp'-sitm. 

HADROSAUR,  Ha'-dTO-sawr. 
HIPPOPOTAMUS,  Sip-po-pSt'-d^m 
HOLOPTYCHIUS,  Hd-vp-tik'-e-w. 
HORNBLENDE,  Horn-blende. 
HYLJEOSAUB,  Hy'-le-o-sawr. 

ICHTHYOSAUB,  Ich'-the-O-80,Wr. 

IGWEOUS,  Ig'-ne-us. 


276 


GLOSSARY. 


IGUANODON,  Ig-wari-o-don. 
INFUSORIA,  In-fu-zo'-re-a. 

LAMELLIBRANCHIATE,  Ld-mel-e-brank'- 

e-ate. 

LEPIDODENDRON,  Lep-e-do-den'-dron. 
LIAS,  Li'-as. 
LIGNITE,  Lig-nlte. 

MASTODON,  Mas'-to-don. 
MEGALOSAUR,  Meg'-a-lo-sawr. 
MEGATHERIUM,  Meg-a-the  '-re-urn. 
METAMORPHIC,  Met-a-mor'-phlc. 
MIOCENE,  Mi'-o-seen. 
MOLLUSCA,  Mol-lus'-ca. 
MORAINE,  M5-rainf. 
MOSASAUR,  Mtf-sa-sawr. 

NODULE,  Nod'-ule. 
NUMMULITE,  Num'-mu-Rte. 

ONTX,  O'-nix. 
OOLITE,  O'-o-Ute. 
ORTHOCERATITE,  Or-tho-cer-a-ftte. 

PALEONTOLOGY,  Pcd-e-on-tol'-o-gy. 
PALEOTHERIUM,  Pal-e-o-the'  '-re-um. 
PALAEOZOIC,  Pal'-e-o-zo-ic. 
PLESIOSAUR,  Ple'-se-o-sawr. 
PLIOCENE,  Pli'-o-seen. 
PORPHYBT,  Porr-fe-ry. 
PROTOZOAN,  Pro-to-zo'-an. 
PTEBICHTHYS,  Ter-ik'-thys. 
PTERODACTTLE,  Ter-ro-dac'-tyl. 


PTEROPOD,  T&J-ro-pod. 
PYRITES,  Py-ri'-teez. 
PYROXENE,  Pir-ox'-een. 

QUARTZ,  Kworts. 

RHIZOPOD,  Klz'-o-pod. 
RAMPHORHYNCUS,  Bam-f&r  f&n'-ku*. 

SAURIAN,  Sdw'-ri-an. 
SELENITE,  S$l'-en-ite. 
SERPENTINE,  Ser'-pen-flne 
SIGILLARIA,  Sig'-U-la'-re-a. 
SILURIAN,  Si-ltt'-re-an. 
SIPHUNCLE,  Sl-funk-Td. 
STALACTITE,  Std-lac'-fite. 
STALAGMITE,  Sta-lag'-rt&te. 
STEATITE,  Ste'-a-tite. 
STIGMARIA,  Stig-md'-re-a. 
STRIA,  Stri-a. 
SYENITE,  Si'-en-ite. 

TALC,  Talc. 

TENTACULITES,  Ten'-tac-u-lit*. 
TOURMALINE,  Toor'-ma-Tin. 
TRACHYTE,  Tra'-kite. 
TRILOBITE,  Trl'-lo-Vite. 
TUFA,  TU'-fa. 

VERD-ANTIQUE,  Verd-an-teek*. 
VERTEBRAE,  Ver'-te-bre. 

WEALDEN,  Weeld'-n. 
ZOOPHYTE,  Ztf-o-fltt. 


Q-AAf 

teiwJJ 

^Vih^  V^AA 
v 

>  .-^A  ^  WW\    rt»  J^  X . 


i  »A\- 


Acalephs,  107. 

Agate,  43. 

Alabaster,  53. 

Albite,  53. 

Alluvial  Deposits,  237. 

Alumina,  48. 

Amethyst,  43. 

Ammonite,  171. 

Amygdaloid,  60. 

Anoplotherium,  203. 

Appalachian  Beach,  140. 

Appalachian  Metamorphism,  164. 

Appalachian  Mountains,  110. 

Appalachian  Revolution,  163. 

Artesian  Wells,  21. 

Articulates,  106. 

Asbestos,  54. 

Athens  Marble,  125. 

Angite,  55. 

Azoic  Time,  98. 

Bad  Lands,  204. 

Basalt,  59. 

Basaltic  Pillars,  63. 

Beetle  Stones,  84. 

Belemnite,  172. 

Bird's  Eye  Limestone,  11T. 

Bird  Tracks,  184. 

Black  River  Limestone,  117. 

Black  Slate,  144. 

Bloodstone,  45. 

Blue  Limestone,  119. 

Bowlders,  208. 

Brachiopods,  107. 

Breccia,  58. 

Bronze  Epoch,  249. 

Bryozoans,  107. 

Buhrstone.  46. 


Calamites,  156. 

Calc  Spar,  49. 

Calcite,  49. 

Cameo,  44. 

Camel,  240. 

Canadian  Divisions,  108. 

Calciferous  Epoch,  112. 

Caflon,  236. 

Cauda  Galli  Grit,  141. 

Carbuncle,  56. 

Carboniferous  Age,  149. 

Carboniferous  Period,  154, 

Carnelian,  43. 

Caves,  153. 

Cave  Bear,  .230. 

Cenozoic  Time,  194. 

Cephalaspis,  137. 

Cephalopods,  107. 

Chalcedony,  43. 

Chalk,  49, 189. 

Chazy  Group,  117. 

Champlain  Epoch,  219. 

Chlorite,  56, 15. 

Chemung  Period,  146.     • 

Chert,  125, 141. 

Chronology,  30. 

Chrysoprase,  43. 

Chrysolite,  59. 

Cimoliasaur,  190. 

Cincinnati  Limestone,  128. 

Clay,  53. 

Clay  Stones,  83. 

Cleavage,  41. 

Cliff  Limestone,  143. 

Clinton  Group,  124. 

Clinkstone,  53. 

Coal,  155. 

Coccoeteus,  135. 


INDEX. 


Comprehensive  Type,  137. 
Conchifers,  107. 
Concretions,  83. 
Conglomerate,  57. 
Conifers.  157. 

Continent,  Outlines  of,  104, 110. 
Coprolites,  174. 
Coral,  108. 

Corniferous  Period,  141. 
Corundum,  49. 
Cretaceous  Period,  187. 
Crinoids,  108, 125. 
Crocodiles,  191. 
Crust  of  Earth,  21. 
Crustaceans,  106. 
Cycad,  170. 

Denudation,  82. 

Deep-Sea  Dredgings,  190. 

Development  Hypothesis,  251. 

Devonian  Age,  134. 

Diatoms,  47. 

Dikes,  86. 

Dinosaur,  181,  191. 

Diorite,  60. 

Dip,  78. 

Diverse  Stratification,  78. 

Dislocations  of  Strata,  76. 

Dolomite,  51. 

Dolerite,  59. 

Drift  Epoch,  207.  - 

Earthquakes,  23. 
Echinoids,  108. 
Echinoderms,  108. 
Elasmosaur,  190. 
Elephant,  227. 
Emery,  49. 
Eocene,  196. 
Escarpment,  78. 
Eurypterus,  130. 
EozoSn  Canadense,  101. 

Faults,  80. 
Feldspar,  53. 
'Fingal's  Cave,  61. 
Flint,  46. 
Folds,  81. 
Fossil,  27.      - 
Fossil  Farina,  48. 
Fucoids,  125, 

Galena  Limestone,  118. 


.Ganoids,  106. 

Garnet,  56. 

Gasteropods,  107. 

Genesee  Slate,  143. 

Geodes.  83. 

Geology,  Definition  of,  20. 

Geysers?,  22. 

Glacial  Epoch,  207. 

Glacial  Striae,  210. 

Glaciers,  29,  212. 

Glyptodon,  230. 

Gneiss,  72. 

Gold  Rocks,  186. 

Goniatite,  144. 

Granite,  67. 

Graptolite,  123. 

Green  Mountains,  122, 131 

Greenstone,  59. 

Gypsum,  52, 129. 

Hadrosaur,  191. 
Hamilton  Period,  142. 
Helderberg  Period,  130. 
Holoptychius,  137. 
Hornstone,  46. 
Hornblende,  54. 
Horse,  240,  250,  271. 
Hot  Springs,  22. 
Hyena,  232. 
Hudson  Period,  122. 
Hudson  River,  123. 

Iceberg,  217. 
Ichthyosaur,  173. 
Iguanodon,  181. 
Igneous  Rocks,  26,  59. 
Infusoria,  105. 
Infusorial  Earth,  48. 
Iron  Epoch,  250. 
Ironstone,  59. 
Irish  Elk,  231. 
Isinglass,  54. 

Jasper,  45. 

Jointed  Structure,  81. 

Jurassic,  167. 

Kaolin,  54. 

Kitchen  Middens,  247. 

Labradorite,  53. 
Labyrinthodon,  183. 
Lselaps,  192. 
Lake  Bottom,  31. 


N  D  EX. 


Lake  Dwellings,  249. 
Lake  Superior,  115. 
Lamellibranch,  107. 
Lamina,  78. 
Lava,  65. 

Lepidodendron,  157. 
Lias,  168. 
Limestone,  49,  58. 
Lingula,  112. 
Lithological  Geology,  35. 
Loess,  237. 

Man,  Coming  of,  243. 

Mammoth  Cave,  153. 

Mammoth,  225. 

Map  of  Azoic  Time,  99. 

Map  of  Mesozoic  Time,  168. 

Map  of  Cenozoic  Time,  195. 

Marble,  51/75. 

Marble,  Carrara,  67. 

Marl;  50. 

Marcellus  Shale,  143. 

Mastodon,  228. 

Medina  Group,  124. 

Megalosaur,  182. 

Megatherium,  229. 

Metal  Age,  248. 

'Metamorphism,  66,  88, 164. 

Metamorphic  Rocks,  65. 

Mesozoic  Time,  166. 

Methods  of  Geological  Study,  23. 

Mica,  54. 

Mica  Schist,  74. 

Millstone  Grit,  154. 

Miocene,  196. 

Mound  Limestone,  125. 

Mountains,  101. 

Mollusks,  106. 

Mosaic  Account,  19, 104, 116,  238. 

Nature,  Uniformity  of,  23. 
Natural  History,  105. 
Nebular  Hypothesis,  17. 
Niagara  Limestone,  124. 
Nummulitic  Limestone,  198. 

Obsidian,  66. 

Offsets,  80. 

Old  Red  Sandstone,  134. 

Oneida  Epoch,  124. 

Onondaga  Group,  141. 

Onyx,  44. 

OOlite,  50, 168. 


Opal,  45. 

Oriskany  Period,  139. 
Orthoceratite,  119. 
Ostrea  Marshii,  170. 
Outcrop,  77. 
Oyeter,  170. 

Palaeozoic  Time,  108. 
Paleotherium,  203. 
Pentamerus,  130. 
Permian,  162. 
'  Phacops  bufo,  146. 
Pine  Barrens,  197. 
Plaster,  52. 
Plesiosaur,  177. 
Pliocene,  196. 
Polyps,  107.  . 
Porphyry,  60. 
Post-Tertiary,  207. 
Potsdam,  111. 
Portage  Group,  146. 
Primeval  Man,  243. 
Protozoans,  105. 
Pterodactyle,  178. 
Pterichthys,  135. 
Pteropods,  107. 
Pudding-stone,  58. 
Pumice,  66. 
Pyroxene,  55. 

Quartz,  40. 
Quartzite,  75. 
Quaternary  Epoch,  207. 
Quincy  Granite,  74. 

Ramphorhynchus,  183. 
Reindeer  Epoch,  245. 
Rhizopods,  100,  188. 
Rhinoceros,  239. 
Rocky  Mountains,  124. 
Rocks,  Classification  of,  57. 
Rocks,  Composition  of,  40. 
Rocks,  Metamorphic,  66. 
Rocks,  Sedimentary,  57. 
Rocks,  Structure  of,  75. 
Rocks,  Stratified,  57,  78. 
Rocks,  Trap,  59. 
Rocks,  Unstratifierf,  b9,  85. 
Rocks,  Volcanic,  65. 

Sand  Dunes,  238. 
Salina  Period,  127. 
Salt  Springs,  129. 


XD  E  X. 


Salt  Beds,  186. 

Sand,  46. 

Sandstone,  57. 

Sapphire,  49. 

Sard,  43. 

Satin  Spar,  53. 

Scenic  Description,  20,  58,  60,  66,  70, 

73,  74,  132,  148,  161, 192,  239. 
Schoharie  Grit,  141. 
Scoria,  66. 

Sculptured  Rocks,  115. 
Sea-weeds,  119,  125. 
Sea-pens,  123. 
Sedimentary  Rocks,  24,  57. 
Selenite,  53. 
Selachians,  106. 
Septaria,  83. 
Serpentine,  56. 
Shale,  58. 
Sigillaria,  157. 
Silica,  40. 
Silicates,  53. 
Silurian  Age,  109. 
Sink-holes,  153. 
Siphuncle,  120. 
Slate,  75,  85. 

Solenhofen  Limestone,  169. 
Soapstone,  54. 
Spirifer  arenosus,  139. 
Spirifer  mucronatus,  146. 
Stalactites,  50. 
Stalagmites,  50. 
Steatite,  55. 

Stone  River  Group,  117. 
St.  Lawrence  River,  123. 
St.  Peter's  Sandstone,  112. 
Stone  Age,  244. 
Stratified  Rocks,  57. 


Stratum,  78. 

Sub-Carboniferous  Period,  153. 
Syenite,  74. 

Talc,  55. 

Talcose  Schist,  75. 
Teliosts,  106. 
Tentaculite,  181. 
Tertiary  Period,  196. 
Terrace  Epoch,  221. 
Theory,  Value  of  a,  252. 
Titanotherium,  205. 
Touchstone,  45. 
Tourmaline,  56. 
Tully  Limestone,  143. 
Turtles,  191. 
Trap-rock,  59. 
Trachyte,,  65. 
Travertine,  49. 
Trenton  Period,  117. 
Trilobite,  112. 
Triassic  Period,  167. 
Tufa,  49. 

Uniformity  of  Nature,  23, 133. 
Upper  Helderberg  Period,  141. 

Verd-antique,  51. 
Veins,  86. 
Vertebrates,  106. 

Water  Lime  Group,  130. 
Wealden,  168. 

Xiphodon,  203. 

Zeuglodon,  202. 
ZoOphite,  110. 


National  Series  of  Standard  Schoot-jBooks. 

DRAWING? 


Chapman's  American  Drawing  Book,  .    •   -*$6  oo 

The  standard  American  text-book  and  authority  in  all  branches  of  art.  A  com- 
pilation of  art  principles.  A  manual  for  the  amateur,  and  basis  of  study  for  the  pro- 
fessional artist.  Adapted  for  schools  and  private  instruction. 

CONTENTS. — "Any  one  who  can  Learn  to  Write  can  Learn  to  Draw." — Primary 
Instruction  in  Drawing. — Rudiments  of  Drawing  the  Human  Head. — Rudiments  in 
Drawing  the  Human  Figure.— Rudiments  of  Drawing.—  The  Elements  of  Geometry.— 
Perspective. — Of  Studying  and  Sketching  from  Nature. — Of  Painting. — Etching  and 
Engraving. — Of  Modeling. — Of  Composition  — Advice  to  the  American  Art-Student. 

The  work  is  of  course  magnificently  illustrated  with  all  the  original  deeigns. 

Chapman's  Elementary  Drawing  Book,  .    .    1  so 

A  Progressive  Course  of  Practical  Exercises,  or  a  text-book  for  the  training  of  tb* 
eye  and  hand.  It  contains  the  elements  from  the  larger  work,  and  a  copy  chould 
be  in  the  hands  of  every  pupil;  while  a  copy  of  the  ''American  Drawing  Book," 
named  above,  should  be  at  hand  for  reference  by  the  class. 

The  Little  Artist's  Portfolio, *50 

25  Drawing  Cards  (progressive  patterns),  25  Blanks,  and  a  fine  Artist's  Pencil, 
all  in  one  neat  envelope. 

Clark's  Elem:n(s  of  Drawing, *i  oo 

A  complete  coirve  i:i  this  graceful  art,  from  the  first  rudiments  of  outline  to  the 
finished  sketches  of  1  riukaipti  and  scenery. 

Fowle's  Linear  and  Perspective  Drawing,  •     *60 

For  the  cuirivitioa  of  the  eye  and  hand,  with  copious  illustrations  and  direc- 
tions for  the  guidance  of  the  unskilled  teacher. 

Monk's  Drawing  Books— Six  lumbers,  per  set,  *2  25 

Each  book  contains  eleven  large  patterns,  with  opposing  blanks.  No.  1.  Elemen- 
tary Studies.  No.  2.  Studies  of  Foliage.  No.  3.  Landscapes.  No.  4.  Animals,  I. 
No.  5.  Animals,  II.  No.  6.  Marine  Views,  etc. 

Allen's  Map-Drawing,   .    .    .    25  cts.;  Scale,       25 

This  method  introduces  a  new  era  in  Map-Drawing,  for  the  following  reasons:— 
1.  It  is  a  system.  This  is  its  greatest  merit. — 2.  It  is  easily  understood  and  taught. 
-^3.  The  eye  i«  trained  to  exact  measurement  by  the  use  of  a  scale.^4.  By  no  spe- 
cial effort  of  the  memory,  distance  and  comparative  size  are  fixed  in  the  mind. — 
5.  It  discards  useless  construction  of  lines.— 6.  It  can  be  taught  by  any  teacher,  even 
though  there  may  have  been  no  previous  practice  in  Map-Drawing.— 7.  Any  pupil 
old  enough  to  study  Geography  can  learn  by  this  System,  in  a  short  time,  to  draw 
accurate  map?. — 8.  The  System  is  not  the  result  of  theory,  but  comes  directly  from 
the  school-room.  It  has  been  thoroughly  and  successfully  tested  there,  with  all 
grades  of  pupil<».— 9.  It  is  economical,  as  it  requires  no  mapping  plates.  It  gives 
Uie  pupil  the  ability  of  rapidly  drawing  accurate  maps. 

Ripley's  Map-Drawing, i  25 

Basod  on  the  Circle.  One  of  the  most  efficient  aids  to  the  acquirement  of  a 
knowledge  of  Geography  is  the  practice  of  map-drawing.  It  is  useful  for  the  same 
reason  that  the  best  exercise,  in  orthography  is  the  writing  of  difficult  words. 
Sight  romes  to  the  aid  of  hearing,  and  a  double  impression  is  produced  upon  the 
memory.  Knowledge  becomes  less  mechanical  and  more  intuitive.  The  student 
who  has  sketched  the  outlines  of  a  country,  and  dotted  the  important  places,  is  littlo 
likely  to  forget  either.  The  impression  produced  may  be  compared  to  that  of  a 
traveller  who  has  been  over  the  ground,  while  more  comprehensive  and  accurate  in 
detail. 

26 


National  Series  of  Standard  School-Books. 


BOOK-KEEPING. 


Folsom's  Logical  Book-keeping,    .   •   .   .   .  $200 
Folsom's  Blanks  to  Book-keeping,   ....  *4  50 

This  treatise  embraces  the  interesting  and  important  discoveries 
of  Prof.  Foleom  (of  the  Albany  "  Bryant  &  Stratton  College"),  fche  par- 
tial enunciation  of  which  in  lectures  and  otherwise  has  attracted  so 
much  attention  in  circles  interested  in  commercial  education. 

After  studying  business  phenomena  for  many  years,  he  has  arrived 
at  the  positive  laws  and  principles  that  underlie  the  whole  subject  of 
Accounts  ;  finds  that  the  science  is  based  in  Value  as  a  generic  term ; 
that  value  divides  into  two  classes  with  varied  species ;  that  all  the 
exchanges  of  values  are  reducible  to  nine  equations  ;  and  that  all  the 
results  of  all  these  exchanges  are  limited  to  thirteen  in  number. 

As  accounts  have  been  universally  taught  hitherto,  without  setting 
out  from  a  radical  analysis  or  definition  of  values,  the  science  has 
been  kept  in  great  obscurity,  and  been  made  as  difficult  to  impart  as 
to  acquire.  On  the  new  theory,  however,  these  obstacles  are  chiefly 
removed.  In  reading  over  the  first  part  of  it,  in  which  the  governing 
laws  and  principles  are  discussed,  a  person  with  ordinary  intelligence 
will  obtain  a  fair  conception  of  the  double  entry  process  of  accounts. 
But  when  he  comes  to  study  thoroughly  theee  laws  and  principles  as 
there  enunciated,  and  works  out  the  examples  and  memoranda  which 
elucidate  the  thirteen  results  of  business,  the  student  will  neither  fail 
in  readily,  acquiring  the  science  as  it  is,  nor  in  becoming  able  intelli- 
gently to  apply  it  in  the  interpretation  of  business. 

Smith  &  Martin's  Book-keeping, 1  25 

Smith  &  Martin's  Blanks, *60 

This  work  is  by  a  practical  teacher  and  a  practical  book-keeper. 
It  is  of  a  thoroughly  popular  class,  and  will  be  welcomed  by  every 
one  who  loves  to  see  theory  and  practice  combined  in  an  easy,  con- 
cise, and  methodical  form. 

The  Single  Entry  portion  is  well  adapted  to  supply  a  want  felt  in 
nearly  all  other  treatises,  which  seem  to  be  prepared  mainly  for  the 
use  of  wholesale  merchants,  leaving  retailers,  mechanics,  farmers, 
etc.,  who  transact  the  greater  portion  of  the  business  of  the  country, 
without  a  guide,.  The  work  is  also  commended,  on  this  account,  for 
general  use  in  Young  Ladies'  Seminaries,  where  a  thorough  ground- 
ing in  the  simpler  form  of  accounts  will  be  invaluable  to  the  future 
housekeepers  of  the  nation. 

The  treatise  on,  Double  Entry  Book-keeping  combines  all  the  ad- 
rantages  of  the  most  recent  methods,  with  the  utmost  simplicity  of 
application,  thus  affording  the  pupil  all  the  advantages  of  actual  ex- 
perience in  the  counting-house,  and  giving  a  clear  comprehension  of 
the  entire  subject  through  a  judicious  course  of  mercantile  trans- 
actions. 

The  shape  of  the  book  is  such  that  the  transactions  can  be  pre- 
sented as  In  actual  practice ;  and  the  simplified  form  of  Blanks- 
three  in  number— adds  greatly  to  the  ease  experienced  in  acquiring 
the  science. 

27 


The  National  Series  of  Standard  School-ftooks. 

NATURAL   SCIENCE. 


FAMILIAR  SCIENCE. 
Norton  &  Porter's  First  Book  of  Science,  •  H  75 

By  eminent  Professors  of  Yale  College.  Contains  the  principles  of  Natural 
Philosophy,  Astronomy,  Chemistry,  Physiology,  and  Geology.  Arranged  on  the 
Catechetical  plan  for  primary  classes  and  beginners. 

Chambers'  Treasury  of  Knowledge,  •   •    •   •    1  25 

Progressive  lessons  upon— -first,  common  things  which  lie  most  immediately 
iround  us,  and  first  attract  the  attention  of  the  young  mind ;  second,  common  objects 
from  the  Mineral,  Animal,  and  Vegetable  kingdoms,  manufactured  articles,  and 
miscellaneous  substances ;  third,  a  systematic  view  of  Nature  under  the  various 
sciences.  May  be  used  as  a  Reader  or  Text-book. 

NATURAL   PHILOSOPHY. 
Norton's  First  Book  in  Natural  Philosophy,  1  oo 

By  Prof.  NOBTON,  of  Yale  College.  Designed  for  beginners.  Profusely  illustrated, 
and  arranged  on  the  Catechetical  plan. 

Peck's  Ganot's  Course  of  Nat.  Philosophy,  .'  1  75 

The  standard  text-book  of  France,  Americanized  and  popularized  by  Prof.  PECK, 
of  Columbia  College.  The  most  magnificent  system  of  illustration  ever  adopted  in 
an  American  school-book  is  here  found.  For  intermediate  classes. 

Peck's  Elements  of  Mechanics, 2  oo 

A  suitable  introduction  to  Bartlett's  higher  treatises  on  Mechanical  Philosophy, 
and  adequate  in  itself  for  a  complete  academical  course. 

Bartlett's  SYNTHETIC,  AND  ANALYTIC,  Mechanics,  -  each   5  oo 
Bartlett's  Acoustics  and  Optics, 3  50 

A  system  of  Collegiate  Philosophy,  by  Prof.  BAKTLETT,  of  West  Point  Military 
Academy. 

Steele's  14  Weeks  Course  in  Philos.  (see  P.  34)    i  50 
Steele's  Philosophical  Apparatus, ....  *125  oo 

Adequate  to  performing  the  experiments  in  the  ordinary  text-books.  The  articles 
will  be  sold  separately,  if  desired. '  See  special  circular  for  details. 

GEOLOGY. 
Page's  Elements  of  Geology, 1  25 

A  volume  of  Chambers'  Educational  Course.  Practical,  simple,  and  eminently 
calculated  to  make  the  study  interesting. 

Emmons'  Manual  of  Geology, 1  25 

The  first  Geologist  of  the  country  has  here  produced  a  work  worthy  of  his  repu- 
tation. 

Steele's  14  Weeks  Course  (seep. 34) i  so 

Steele's  Geological  Cabinet, *4o  oo 

Containing  125  carefully  selected  specimens.    In  four  parts.    Sold  separately,  U 


desired.    See  circular  for  details. 

28 


The  National  Series  of  Standard  School-fiooks. 

NATURAL    SCIENCE-Continued. 

CHEMISTRY. 

Porter's  First  Book  of  Chemistry,  ....  .$100 
Porter's  Principles  of  Chemistry, 2  oo 

The  above  are  widely  known  as  the  productions  of  one  of  the  most  eminent  scien- 
tific men  of  America.  The  extreme  simplicity  iu  the  method  of  presenting  the 
science,  while  exhaustively  treated,  has  excited  universal  commendation. 

Darby's  Text-Book  of  Chemistry, 1  75 

Purely  a  Chemistry,  divesting  the  subject  of  matters  comparatively  foreign  to  it 
(such  as  heat,  light,  electricity,  etc.),  but  usually  allowed  to  engross  too  much  atten- 
tion in  ordinary  school-books. 

Gregory's  Organic  Chemistry, 2  50 

Gregory's  Inorganic  Chemistry, 2  50 

The  science  exhaustively  treated.    For  colleges  and  medical  students. 

Steele's  Fourteen  Weeks  Course, 1  so 

A  successful  effort  to  reduce  the  study  to  the  limits  of  a  single  term,  thereby 
making  feasible  its  general  introduction  in  institutions  of  every  character.  The 
author's  felicity  of  style  and  success  in  making  the  science  pre-eminently  interest- 
ing are  peculiarly  noticeable  features.  (See  page  34.) 

Steele's  Chemical  Apparatus, •   -*ao  oo 

Adequate  to  the  performance  of  all  the  important  experiments. 

BOTANY. 
Thinker's  First  Lessons  in  Botany,  ....      40 

For  children.  '  The  technical  terms  are  largely  dispensed  with  in  favor  of  an 
easy  and  familiar  style  adapted  to  the  smallest  learner. 

Wood's  Object-Lessons  in  Botany,  ....  1  so 
Wood's  American  Botanist  and  Florist,  •  •  2  so 
Wood's  New  Class-Book  of  Botany, ....  3  so 

The  standard  text-books  of  the  United  States  in  this  department.  In  style  they 
are  simple,  popular,  and  lively ;  in  arrangement,  easy  and  natural ;  in  description, 
graphic  and  strictly  exact.  The  Tables  for  Analysis  are  reduced  to  a  perfect  sys- 
tem. More  are  annually  sold  than  of  all  others  combined. 

Wood's  Plant  Record, *75 

A  simple  form  of  Blanks  for  recording  observations  in  the  field. 

Wood's  Botanical  Apparatus, *8  oo 

A  portable  Trunk,  containing  Drying  Press,  Knife,  Trowel,  Microscope,  and 
Tweezers,  and  a  copy  of  Wood's  Plant  Kecord— composing  a  complete  outfit  for 
the  collector. 

Young's  Familiar  Lessons,  •   •   • 2  °° 

Darby's  Southern  Botany,  .    . .   2  oo 

Embracing  general  Structural  and  Physiological  Botany,  with  vegetable  products, 
and  descriptions  of  Southern  plants,  and  a  complete  Flora  of  the  Southern  States, 

30 


The  National  Xcrfes  of  Standard 

NATURAL    SCIENCE-Continued. 

PHYSIOLOGY. 

Jarvis'  Elements  of  Physiology, $75 

Jarvis'  Physiology  and  Laws  of  Health,    .  1  GO 

The  only  books  extant  which  approach  this  subject  with  a  proper  view 
of  the  tru«  object  of  teaching  Physiology  in  schools,  viz.,  that  scholars 
may  know  how  to  take  care  of  their  own  health.  In  bold  eontrast  with 
the  abstract  Anatomies,  which  children  learn  as  they  would  Greek  or 
Latin  (and  forget  as  soon),  to  discipline  the  mind,  are  these  text-books, 
using  the  science,  as  a  secondary  consideration,  nnd  only  so  far  as  is 
necessary  for  the  comprehension  of  the  laws  of  health. 

Hamilton's  Vegetable  &  Animal  Physiology,  1  25 

The  two  branches  of  the  science  combined  in  one  volume  lead  the  stu- 
dent to  a  proper  comprehension  of  the  Analogies  of  Nature. 

Steele's  Fourteen  Weeks  Course  (see  p.  34),  .  i  50     • 

ASTRONOMY. 
Steele's  Fourteen  Weeks'  Course, 1  so 

Reduced  to  a  single  term,  and  better  adapted  to  school  use  than  any 
work  heretofore  published.  Not  written  for  the  information  of  scientific 
men,  but  for  the  inspiration  of  youth,  the  pages  are  not  burdened  with  a 
multitude  of  figures  which  no  memory  could  possibly  retain.  The  whole 
subject  is  presented  in  a  clear  and  concise  form.  (See  p.  34.) 

Willard's  School  Astronomy, 1  oo 

By  means  of  clear  and  attractive  illustrations,  addressing  the  eye  in 
many  cases  by  analogies,  careful  definitions  of  all  necessary  technical 
terms,  a  careful  avoidance  of  verbiage  and  unimportant  matter,"  particular 
nttention  to  analysis,  and  a  general  adoption  of  the  simplest  methods, 
Mrs.  Willard  has  made  the  best  and  most  attractive  elementary  Astron- 
omy extant 

Mclntyre's  Astronomy  and  the  Globes,    •    ••  1  so 

A  complete  treatise  for  intermediate  classes.     Highly  approved. 

Bartlett's  Spherical  Astronomy, 5  oo 

Th«  West  Point  course,  for  advanced  classes,  with  applications  to  the 
current  wants  of  Navigation,  Geography,  and  Chronology. 

NATURAL  HISTORY. 
Carll's  Child's  Book  of  Natural  History,  .    .  0  50 

Illustrating  the  Animal,  Vegetable,  and  Mineral  Kingdoms,  wit*  appli- 
cation to  the  Arts.  For  beginners.  Beautifully  and  copiously  illustrated. 

ZOOLOGY. 
Chambers'  Elements  of  Zoology, 1  50 

A  complete  and  comprehensive  system  of  Zoology,  adapted  for  aca- 
demic Instruction,  presenting  a  systematic  view  of  the  Animal  Kingdom 
as  a  portion  of  external  Nature. 

82 


National  Series  of  Standard  School-tBooks. 

LITERATURE. 

Cleveland's  Compendiums    ....   each,  8*2  60 

ENGLISH  LITERATURE.  AMERICAN  LITERATURE. 

ENGLISH  LITERATURE  OF  THE  XIXTH  CENTURY. 

In  these  volumes  are  gathered  the  cream  of  the  literature  of  the  English  speak, 
ing  people  for  the  school-room  and  the  general  reader.  Their  reputation  i» 
mtional.  More  than  125,000  copies  have  been  sold. 

Boyd's  English  Classics each,    *l  25 

MILTON'S  PARADISE  LOST.  THOMSON'S  SEASONS. 

YOUNG'S  NIGHT  THOUGHTS.  POLLOK'S  COURSE  OF  TIME. 

COWPER'S  TASK,  TABLE  TALK,  &c.    LORD  BACON'S  ESSAYS. 

This  series  of  annotated  editions  of  great  English  writers,  in  prose  and  poetry, 
is  designed  for  critical  reading  and  parsing  in  schools.  Prof.  J.  K.  Boyd  proves 
himself  an  editor  of  high  capacity,  and  the  works  themselves  need  no  encomium. 
As  auxiliary  to  the  study  of  Belles  Lettres,  etc.,  these  works  have  no  equal. 

Pope's  Essay  on  Man    .........     *20 

Pope's  Homer's  Iliad *so 

The  metrical  translation  of  the  great  poet  of  antiquity,  and  the  matchless 
'•k  Essay  on  the  Nature  and  State  of  Man,1'  by  ALEXANDER  POPE,  afford  superior 
exercise  in  literature  and  parsing. 

AESTHETICS. 


Huntinglon's  Manual  of  the  Fine  Arts  •    -*i  75 

A  view  of  the  rise  and  progress  of  Art  in  different  countries,  a  brief 
account  of  the  most  eminent  masters  of  Art,  and  an  analysis  of  the  prin- 
ciples of  Art.  It  is  complete  in  itself,  or  may  precede  to  advantage  tno 
critical  work  of  Lord  Kames. 

Boyd's  Kames'  Elements  of  Criticism    •   -*i  75 

The  best  edition  of  this  standard  work ;  without  the  study  of  which 
none  may  be  considered  proficient  in  the  science  of  the  Perceptions.  No 
other  study  can  be  pursued  with  so  marked  an  effect  upon  the  taste  and 
refinement  of  the  pupil. 

POLITICAL  ECONOMY. 


Champlin's  Lessons  on  Political  Economy    l  25 

.tises. 
jf  rei 

36 


An  improvement  on  previous  treatises,  being  shorter,  yet  containing 
every  thing  essential,  with  a  view  of  recent  questions  in  finance,  etc., 
which  is  not  elsewhere  found. 


The  National  Series  of  Standard  School- 


GERMAN. 


A  COMPLETE  COUKSE  IN  THE  GEEMAN, 

By  JAMES   H.  WORMAN,  A.  M. 

Worrnan's  Elementary  German  Grammar  -$i  50 
Ytforman's  Complete  German  Grammar      •  2  oo 

\  These  volumes  are  designed  for  intermediate  and  advanced  classes  respectively. 

Though  following  the  same  general  method  with  "Otto"  (that  of  lGaspey'> 
smr  author  differs  essentially  in  its  application.  He  is  more  practical,  more  syd" 
tematic,  more  accurate,  and  besides  introduces  a  number  of  invaluable  feature* 
which  have  never  before  been  combined  in  a  German  grammar. 

Among  other  things,  it  may  be  claimed  for  Prof.  Worman  that  he  has  been 
the  first  to  introduce  in  an  American  text-book  for  learning  German,  a  system 
of  analogy  and  comparison  with  other  languages.  Our  best  teachers  are  also 
enthusiastic  about  his  methods  of  inculcating  the  art  of  speaking,  of  understanding 
the  spoken  language,  of  correct  pronunciation ;  the  sensible  and  convenient  origi' 
nal  classification  of  nouns  (in  four  declensions),  and  of  irregular  verbs,  also  de- 
serves much  praise.  We  also  note  the  use  of  heavy  type  to  indicate  etymological 
changes  in  the  paradigms^  »nd,  in  the  exercises,  the  parts  which  specially  illustrate 
preceding  rules. 

Worman's  Elementary  German  Reader   .    .    1  25 
Worman's  Collegiate  German  Reader  .    .    .    2  oo 

The  finest  and  most  judicious  compilation  of  classical  and  standard  German 
Literature.     These  works  embrace,  progressively  arranged,  selections  from  the 
masterpieces  of  Goethe,  Schiller,  Korner,  Seumte,  Uhland,  Freiligrath,  Heine, 
Schlegel,  Holty,  Lenau,  Wieland,  Herder,  Lessing,  Kant,  Fiehte,  Schelling,  Win- 
kelmann,  Humboldt,  Eanke,  Raumer,  Menzel,  Gervinus,  &c.,  and  contains  com- 
plete Goethe's  "  IpLigenie,"  Schiller's  "  Jungfrau;"  also,  for  instruction  in  mod- 
ern conversational  German,  Benedix's  "  Eigensinn." 

There  are  besides,  Biographical  Sketches  of  each  author  contributing,  Notes, 
explanatory  and  philological  (after  the  text),  Grammatical  References  to  all  lead- 
Ing  grammars,  as  well  as  the  editor's  own,  and  an  adequate  Vocabulary. 

Worman's  German  Echo l  25 

Consists  of  exercises  in  colloquial  style  entirely  in  the  German,  with  an  ade- 
quate vocabulary,  not  only  of  words  but  of  idioms.  The  object  of  the  system  de- 
veloped in  this  work  (and  its  companion  volume  in  the  French)  is  to  break  up  the 
laborious  and  tedious  habit  of  translating  the  thoughts,  which  is  the  student's 
most  effectual  bar  to  fluent  conversation,  and  to  lead  him  to  think  in  the  language 
in  which  he  speaks.  As  the  exercises  illustrate  scenes  in  actual  life,  a  considera- 
ble knowledge  of  the  manners  and  customs  of  the  German  people  is  also  acquired 
from  the  use  of  this  manual. 

Worman's  German  Copy-Books, !  Numbers,  each     15 

On  the  same  plan  aB  the  most  approved  systems  for  English  penmanship,  with 
progressive  copies. 

43 


The  National  Series  of  Standard  School-2>ooks. 

CHARTS. 


McKenzie's  Elocutionary  Chart, $3  50 

Baade's  Reading  Case,  .;'.;. *io  <x 

This  remarkable  piece  of  school-room  furniture  is  a  receptacle  containing  a  num 
her  of  primary  cards.  By  an  arrangement -of  slides  on  the  front,  one  sentence  at  n 
time  is  shown  to  the  class.  Twenty-eight  thousand  transpositions  may  be  made, 


ing  a  variety  of  progressive  exercises  which  no  other  piece  of  apparatus 
offers.    One  of  its  best  features  is,  that  it  is  so  exceedingly  simple  as  not  to  get  out 


Bffordi 
offers. 
of  order,  while  it  may  be  operated  with  one  finger. 

Marcy's  Eureka  Tablet, *i  so 

A  new  system  for  the  Alphabet,  by  which  it  may  be  taught  without  fail  in  nine 
lessons. 

Scofield's  School  Tablets, *8  oo 

On  Five  Cards,  exhibiting  Ten  Surfaces.  These  Tablets  teach  Orthography, 
Reading,  Object-Lessons,  Color,  Form,  etc. 

Watson's  Phonetic  Tablets, .    .  *8  oo 

Four  Cards,  and  Eight  Surfaces ;  teaching  Pronunciation  and  Elocution  phonetic- 
auy — for  class  exercises. 

Page's  Normal  Chart, *3  75 

The  whole  science  of  Elementary  Sounds  tabulated.  By  the  author  of  Page's 
Theory  and  Practice  of  Teaching. 

Clark's  Grammatical  Chart, *3  75 

Exhibits  the  whole  Science  of  Language  in  one  comprehensive  diagram. 

Davies'  Mathematical  Chart,  •   - *75 

Mathematics  made  simple  to  the  eye. 

Monteith's  Reference  Maps  (School  Series),  .   .*so  oo 

Eight.  Numbers.  Mounted  on  Rollers.  Names  all  laid  down  in  small  type,  so 
that  to  the  pupil  at  a  short  distance  they  are  Outline  Maps,  while  they  serve  as 
their  own  key  to  the  teacher. 

Willard's  Chronographers, Each,  *2  oo 

Historical.  Four  Numbers.  Ancient  Chronographei ;  English  Chronographer; 
American  Chronographer ;  Temple  of  Time  (general).  Dates  and  Events  repre- 
sented to  the  eye. 

APPARATUS. 

Harrinqion's  Geometrical  Blocks,    •   *   *   **$10  00 

These  patented  blocks  are  hinged,  so  that  each  form  can  be  dissected. 

Harrington's  Fractional  Blocks, *8  °° 

Steele's  Chemical  Apparatus,  .    .  *so  oo 

Steele's  Philosophical  Apparatus,  (see  p.ss)  *125  oo 
Steele's  Geological  Cabinet,  (^e  p.28)  .  .  .  *40  oo 
Wood's  Botanical  Apparatus,  (see  p.so )  .  .  *8  oo 
Bock's  Physiological  Apparatus,  ....  175  oo 

47 

12   92  08 


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LIBRARY,  UNIVERSITY  OF  CALIFORNIA,  DAVIS 

Book  Slip-50m-5,'70(N6725s8) 458— A-31/5 


730457 


Steele,  J.D. 

The  story  of  the 
rocks. 


Call  Number: 

QE28 
S799 


N9  730457 


QE28 

Steele,  J.D.  S799 

The  story  of  the  rocks. 

PHYSICAL 
SCIENCES 
LIBRARY 


LIBRARY 

UNIVERSITY  OF  CALIFORNIA 
DAVIS 


